LAPORAN AKHIR PENELITIAN PROTOTIPE DANA ITS 2020

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s

LAPORAN AKHIR

PENELITIAN PROTOTIPE

DANA ITS 2020

PROTOTIPE PEMBUATAN SHOCK ABSORBER UNTUK

MOTOR LISTRIK (GESITS)

DALAM RANGKA MENINGKATKAN TKDN

Tim Peneliti :

Yuli Setiyorini, ST., MPhil., PhD. Eng (Teknik Material dan Metalurgi/F.Indsys/ITS)

Sungging Pintowantoro, ST., MT., PhD (Teknik Material dan Metalurgi/F.Indsys/ITS)

Fakhreza Abdul, ST., MT (Teknik Material dan Metalurgi/F.Indsys/ITS)

DIREKTORAT RISET DAN PENGABDIAN KEPADA MASYARAKAT

INSTITUT TEKNOLOGI SEPULUH NOPEMBER

SURABAYA

2020

Sesuai Surat Perjanjian Pelaksanaan Penelitian No: 889/PKS/ITS/2020

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LEMBAR PENGESAHAN LAPORAN AKHIR

1. Judul Penelitian : Prototipe Pembuatan Shock Absorber Untuk Motor Listrik (GESITS)

Dalam Rangka Meningkatkan TKDN

2. Ketua Tim

a. Nama : Yuli Setiyorini S.T., M.Phil., Ph.D

b. Jenis Kelamin : Perempuan

c. NIP : 197907242005012003

d. Jabatan Fungsional : Lektor

e. Pangkat : Penata

f. Fakultas/Jurusan : Fakultas Teknologi Industri dan Rekayasa Sistem/

Teknik Material dan Metalurgi

g. Laboratorium :

h. Tim :

No

Nama Lengkap

Peran

Dalam

Tim

Fakultas/Jurusan/Unit Instansi/Perguruan

Tinggi

1 Dr. Sungging

Pintowantoro S.T.,M.T. Anggota

FT-IRS/Departemen Teknik

Material dan Metalurgi ITS

2 Fakhreza Abdul

S.T.,M.T. Anggota

FT-IRS/Departemen Teknik

Material dan Metalurgi ITS

3 Fahny Ardian Mahasiswa - ITS

4 Ferian Surya

Rahmaadana Mahasiswa - ITS

3. Dana dan Waktu:

a. Jangka waktu program yang diusulkan : 1 Tahun

b. Biaya yang disusulkan : Rp. 60.000.000

c. Biaya yang disetujui tahun 2020 : Rp. 60.000.000

Menyetujui

Ketua Tim Peneliti

Yuli Setiyorini S.T., M.Phil., Ph.D

NIP. 197907242005012003

Surabaya, 30 November 2020

Menyetujui

Direktur Riset dan Pengabdian Masyarakat

Agus Muhamad Hatta, S.T, M.Si, Ph.D

NIP. 197809022003121002

Mengetahui

Kepala Pusat Unggulan ITS Desain

Dr. Ir. Bambang Iskandriawan, M.Eng

NIP. 196011221990021001

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DAFTAR ISI

DAFTAR ISI.................................................................................................................................... ii

DAFTAR TABEL .......................................................................................................................... iii

DAFTAR GAMBAR ...................................................................................................................... iv

DAFTAR LAMPIRAN ................................................................................................................... v

BAB I RINGKASAN ...................................................................................................................... 1

BAB II HASIL PENELITIAN ...................................................................................................... 2

BAB III STATUS LUARAN ....................................................................................................... 16

BAB IV PERAN MITRA ............................................................................................................. 17

BAB V KENDALA PELAKSANAAN PENELITIAN .............................................................. 18

BAB VI RENCANA TAHAPAN SELANJUTNYA .................................................................. 19

BAB VII DAFTAR PUSTAKA ..................................................................................................... v

BAB VIII LAMPIRAN .................................................................................................................. vi

iii

DAFTAR TABEL

Tabel 2.1 Variabel Penelitian ........................................................................................................... 4

Tabel 2.2 Material Properties ........................................................................................................... 4

Tabel 2.3 Maximum Von Mises Stress of shock absorber made from AISI A228 + ASTM 40 ..... 4

Tabel 2.4 Maximum Von Mises Stress of shock absorber made from AISI 347 + ASTM 40 ....... 4

Tabel 2.5 Fatigue analyses were performed according to Goodman, Soderberg and Gerber ......... 7

Tabel 2.6 Minimum Safety Factor of Shock Absorber for AISI 347+ASTM 40 ............................ 7

Tabel 2.7 Minimum Safety Factor of Shock Absorber for ASTM A228+ASTM 40 ...................... 7

Tabel 2.8 Result Modal Analysisi Revolution 5 mm (AISI 347)..................................................... 8

Tabel 2.9 Result Modal Analysisi Revolution 5 mm (ASTM 228) ................................................. 8

Tabel 2.10 Input dan output pada Analisa permodelan .................................................................. 12

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DAFTAR GAMBAR

Gambar 2.1 Komponen Shock Absorber ........................................................................................ 2

Gambar 2.2 Pegas (Spring) ............................................................................................................. 3

Gambar 2.3 Desain Shock Abosrber setelah assembly ................................................................... 3

Gambar 2.4 Stress Distribution ASTM 228+ASTM 40 Pitch ........................................................ 5

Gambar 2.5 Stress Distribution ASTM 228+ASTM 40 Revolution ............................................... 5

Gambar 2.6 Stress Distribution AISI 347+ASTM 40 Pitch ............................................................ 6

Gambar 2.7 Stress Distribution AISI 347+ASTM 40 Revolution .................................................. 6

Gambar 2.8 Modal Analysis ............................................................................................................ 8

Gambar 2.9 Total Deformation AISI 347 (Revolution, 5 mm) ....................................................... 9

Gambar 2.10 Total Deformation ASTM A228 (Revolution, 5 mm)............................................. 10

Gambar 2.11 Geometri dan desain shock abosrber ....................................................................... 11

Gambar 2.12 Komponen yang akan dilakukan Investment Casting ................................................... 13

Gambar 2.13 Komponen yang akan dilakukan Hot Rolling ............................................................... 13

Gambar 2.14 Hasil Simulasi Casting dengan menggunakan Software ANSYS 19.1 ................... 14

Gambar 2.15 Hasil dari Investment Casting dan Rolling .............................................................. 15

Gambar 2.16 Prototipe Produk Shock Absorber ........................................................................... 15

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DAFTAR LAMPIRAN

Lampiran 1 Tabel Daftar Luaran .................................................................................................... vi

Lampiran 2 Bukti i-MAMM 2020 ................................................................................................ vii

Lampiran 3 Bukti ICOMMET 2020 ............................................................................................ viii

Lampiran 4 Bukti Conference di ICOMMET 2020 (ITS SURABAYA) ...................................... ix

Lampiran 5 Draft HKI ..................................................................................................................... x

Lampiran 6 Draft Paper untuk ICOMMET 2020 ITS ................................................................... xx

Lampiran 7 Draft Paper untuk i-MAMM 2020 UI ..................................................................... xxx

Lampiran 8 Draft untuk Jurnal Material & Design ....................................................................... xli

1

BAB I RINGKASAN Meningkatnya jumlah kendaraan roda dua seiring dengan meningkatnya mobilitas

penduduk di Indonesia menyebab banyak populasi dan keborosan pemakaian bahan bakar.

Oleh karenanya, kendaraan roda dua listrik menjadi suatu alternative untuk menjawab

permasalahan tersebut. Indonesia juga berusaha menghadirkan kendaraan roda listrik buatan

local yaitu GESITS. Kemandirian dalam produksi komponen kendaraan juga menjadi

perhatian, terutama dalam meningkatkan TKDN. Salah satu tantangan adalah bagaimana

mampu membuat komponen suspense untuk kendaraan roda dua listrik [1][2].

Dalam penelitian ini kami akan melakukan design dan pemilihan material dalam rangka

membuat prototype shock absorber GESITS, yang nantinya akan digunakan. Hal ini untuk

melanjutkan diskusi dengan PT. WIKA yang akan melakukan kerjasama dengan kami dalam

rangka pemenuhan komponen kendaraan listrik roda dua.

2

BAB II HASIL PENELITIAN Bentuk dan ukuran komponen shock absorber sangat berpengaruh terhadap performa

shock absorber selama berkendara. Desain shock absorber harus sesuai dengan kendaraan.

Pada penelitian ini rangkaian desain shock absorber dengan model dan diameter pegas yang

berbeda ditunjukkan pada Gambar 3.1-3.3 dan Tabel 3.1. Pegas dengan model dan diameter

yang berbeda pada umumnya memiliki konsentrasi tegangan dan distribusi tegangan yang

berbeda dan mungkin dapat meningkatkan umur dan faktor keamanan komponen. Pegas

dengan diameter besar memberikan distribusi tegangan yang maksimal. Namun, hal itu akan

meningkatkan bobot dari shock absorber dan meningkatkan konsumsi energi kendaraan.

Sedangkan pegas dengan diameter minimum akan menurunkan berat shock absorber dan

meningkatkan kemungkinan terjadinya kegagalan akibat konsentrasi tegangan dan distribusi

tegangan yang buruk. Oleh karena itu, penelitian ini perlu dilakukan untuk mendapatkan desain

shock absorber yang optimal baik dari segi bobot, sifat mekanik yang baik dan kenyamanan

saat berkendara. Pada penelitian ini dihasilkan 6 desain shock absorber yang berbeda dengan

model dan diameter pegas yang bervariasi untuk mendapatkan desain shock absorber terbaik

[3][4][5][6].

Komponen terpenting dari shock absorber adalah upper mount, piston rod, cylinder dan

lower mount. Semua komponen shock absorber yang berbeda dibuat terpisah dalam perangkat

lunak SolidWorks 2014 dan semua bagian shock absorber dirakit di SolidWorks 2014. Di

bagian bawah shock absorber, sebagai fix support untuk menahan gaya yang bekerja pada

shock absorber seperti yang ditunjukkan pada Gambar 3.3. Setiap kali beban eksternal tertentu

diterapkan pada bagian atas shock absorber, silinder shock absorber bergerak ke bawah dan

menekan pegas. Pembebanan ini mempresentasikan sebagai pembebanan akibat berat

kendaraan dengan dua penumpang [1][7][8]

Gambar 2.1 Komponen Shock Absorber

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Gambar 2.2 Pegas (Spring)

Gambar 2.3 Desain Shock Abosrber setelah assembly

Model shock absorber untuk FEA dibuat di SolidWorks 2014. Model yang dibuat

kemudian diimpor di ANYS 19.1 menggunakan ekstensi parasolid. Analisa struktural static

dan modal analysis pada shock absorber dilakukan untuk menghitung safety factor. Analisis

statik dilakukan dengan menggunakan bobot rata-rata kendaraan dan dua penumpang (7500

N). Material Peredam kejut dianggap sebagai material yang memiliki isotropik elastis linier.

Tabel 3.2 menunjukkan properti ASTM A231 dan AISI 9255 untuk pegas peredam kejut dan

ASTM 40 untuk komponen atas dan bawah. Kontak permukaan standar ditentukan antara

komponen bawah dan atas. Koefisien gesekan sebesar 0,1 diasumsikan karena komponen

umumnya terlumasi dengan baik oleh fluida [9]. Untuk mengevaluasi perbedaan hasil analisis

struktur dan modal statik satu sama lain desain shock absorber, dengan variasi material, model

4

dan diameter pegas. . Analisis elemen hingga shock absorber dilakukan dengan menggunakan

ANSYS 19.1 pada PC prosesor Intel P4 2.0 GHz [10].

Tabel 2.1 Variabel Penelitian

Table 2.2 Materials Properties [17]

Table 2.3 Maximum Von Mises Stress of shock absorber made from AISI A228 + ASTM 40

Tabel 2.4 Maximum Von Mises Stress of shock absorber made from AISI 347 + ASTM 40

Materials Spring Model Diameter of Spring (mm)

AISI 347

Pitch

5

7

9

Revolution

5

7

9

ASTM A228

Pitch

5

7

9

Revolution

5

7

9

Materials Young Modulus

(GPa) Possion Ratio

Yield Strength

(MPa)

UTS

(MPa)

Density

(gr/cm3)

ASTM 40 180 0,29 200 310 7,5

AISI 347 195 0,27 450 690 7,93

ASTM A228 200 0,29 350 650 7,8

Materials Spring Model Diameter of Spring

(mm)

Maximum Von Misses

Stress (MPa)

Maximum Von

Misses Stress (MPa)

Total

Deformation

(mm)

ASTM 228

&

ASTM 40

Pitch

5 145,12 0,019418 23,264

7 162,86 0,014267 22,822

9 221,08 0,0071345 21,94

Revolution

5 143,95 0,021644 23,25

7 181,77 0,021644 22,81

9 231,38 0,0044108 21,742


(mm)

Maximum Von Misses

Stress (MPa)

Maximum Von

Misses Stress (MPa)

Total

Deformation

(mm)

AISI 347

&

ASTM 40

Pitch

5 145,13 0,020342 23,266

7 161,28 0,01298 22,828

9 218,46 0,0064006 21,952

Revolution

5 143,98 0,027197 23,252

7 179,99 0,028123 22,815

9 229,21 0,0048745 21,753

5

FEA dari peredam kejut dilakukan dengan menggunakan ANSYS 19.1.Optimasi dalam

penelitian ini adalah memastikan bahwa desain shock absorber memiliki nilai safety factor

yang besar. Tegangan ekivalen maksimum pada peredam kejut harus lebih rendah dari batas

daya tahan luluh material. Selain itu, tekanan pada desain shock absorber harus didistribusikan

secara merata. Stres von Mises diadopsi sebagai kriteria dalam penelitian ini. Kriteria hasil von

Mises adalah bagian dari teori plastisitas yang paling baik diterapkan pada bahan ulet, seperti

logam. Sebelum menghasilkan simulaso, respon material diasumsikan elastis. Dalam ilmu

material dan teknik, kriteria hasil von Mises dapat dirumuskan dalam istilah tegangan von

Mises. Tegangan von Mises digunakan untuk memprediksi hasil material dalam kondisi

pembebanan apapun dari hasil uji tarik uniaksial sederhana. Oleh karena itu, tegangan von

Mises juga telah banyak digunakan dalam analisis elemen hingga sambungan buatan. Gambar

3.5-3.6 menunjukkan tegangan von Mises pada desain shock absorber yang dibuat dari ASTM

A231 di bawah pembebanan statis. Gambar 3.6 -3.7 menunjukkan tegangan von Mises pada

desain peredam kejut yang terbuat dari AISI 9255 dengan beban statis. Hasil yang disajikan

dalam penelitian ini menunjukkan bahwa saat shock absorber dibebani. Dari hasil tersebut

dapat disimpulkan bahwa desain shock absorber berbahan ASTM A231 dan AISI 9255 aman

karena tegangan miss maksimum di bawah titik luluh material. Selain itu desain peredam kejut

yang terbuat dari bahan AISI 9255 dengan model revolusi dan pegas berdiameter 6 mm

merupakan desain terbaik untuk kondisi pembebanan statis.[5][11]

Gambar 2.4 Stress Distribution ASTM 228 + ASTM 40 Pitch

Gambar 2.5 Stress Distribution ASTM 228 + ASTM 40 Revolution

5 mm

5 mm 7 mm

7 mm 9 mm

9 mm

6

Teori Goodman, Soderberg dan Gerber digunakan untuk menentukan faktor keamanan

(safety factor) desain shock absorber. Pada penelitian ini faktor keamanan shock absorber

dievaluasi menggunakan ANSYS Workbench. Perhitungan faktor keamanan shock absorber

dilakukan untuk bahan ASTM A231 dan AISI 9255. Dalam FEA, bahan dianggap elastisitas

isotropik. Oleh karena itu, faktor keamanan dipastikan lebih dari 1 yang menyimpulkan desain

shock absorber aman. Rumusan teori goodman, soderberg dan gerber dapat dilihat pada Tabel

3.5 [2] [8].

N : safety factor

Se : endurance limit

Su : ultimate tensile strength

𝜎𝑚 : mean stress

𝜎𝑎 : alternating stress

𝜎𝑚 =(𝜎𝑚𝑎𝑥+𝜎𝑚𝑖𝑛)

2 (1)

𝜎𝑎 =(𝜎𝑚𝑎𝑥− 𝜎𝑚𝑖𝑛)

2 (2)

Gambar 2.6. Stress Distribution AISI 347 + ASTM 40 Pitch

Gambar 2.7 Stress Distribution AISI 347 + ASTM 40 Revolution

5 mm

5 mm

7 mm

7 mm

9 mm

9 mm

7

Tabel 2.5 Fatigue analyses were performed according to Goodman, Soderberg and Gerber

Tabel 2.6. Minimum Safety Factor of Shock Absorber for AISI 347+ASTM 40

Tabel 2.7 Minimum Safety Factor of Shock Absorber for ASTM A228+ASTM 40

Dari Tabel 3.6-3.7, kita dapat melihat bahwa semua desain peredam kejut memiliki

nilai faktor keamanan yang berbeda, sesuai dengan semua teori kelelahan tetapi semua peredam

kejut memiliki faktor keamanan lebih dari 1. Ini berarti bahwa semua desain peredam kejut

adalah desain yang baik dan aman di bawah pembebanan statis. Di antara desain shock

absorber, desain model pitch dan pegas berdiameter 6 mm berbahan AISI 9255 lebih baik dari

yang lain. Karena desain ini memiliki nilai faktor keamanan yang lebih tinggi di semua teori

faigue. Nilai deformasi shock absorber disajikan pada Tabel 3.3-3.4.

MODAL ANALYSIS

Analisis modal membantu menentukan karakteristik getaran (frekuensi alami dan

bentuk mode) dari struktur atau komponen mekanis, yang menunjukkan pergerakan berbagai

bagian struktur dalam kondisi pembebanan dinamis, seperti yang disebabkan oleh gaya lateral

yang dihasilkan oleh aktuator elektrostatis. Frekuensi alami dan bentuk mode merupakan

parameter penting dalam desain struktur untuk kondisi pembebanan dinamis. Analisis modal

Fatigue Theories Formulas

Goodman (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑢

) =1

𝑁

Soderberg (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑦

) =1

𝑁

Gerber (𝑁. 𝜎𝑎

𝑆𝑒

) + (𝑁. 𝜎𝑚

𝑆𝑢

)2

= 1


(mm) Goodman Soderberg Gerber

AISI 347

&

ASTM 40

Pitch

5 2,951138 2,531972 3,649086

7 2,655561 2,278404 3,283584

9 1,960453 1,682036 2,424074

Revolution

5 2,974764 2,552218 3,678319

7 2,379584 2,041592 2,942363

9 1,868502 1,603146 2,310375


(mm) Goodman Soderberg Gerber

ASTM 228

&

ASTM 40

Pitch

5 2,780242 2,195982 3,437771

7 2,477353 1,95677 3,063233

9 1,82492 1,44146 2,256489

Revolution

5 2,802896 2,213841 3,465802

7 2,219654 1,753207 2,744599

9 1,743661 1,377289 2,156007

8

shock absorber dilakukan dengan menggunakan software ANSYS. Gambar 3.8 menunjukkan

bentuk mode peredam kejut pada frekuensi dasarnya dan Tabel 3.8-3.9 menunjukkan frekuensi

alami desain peredam kejut untuk berbagai mode getarannya.

Analisis modal biasanya digunakan untuk menentukan karakteristik getaran (frekuensi

alami dan bentuk mode) dari suatu struktur atau komponen mesin saat sedang dirancang. Ini

juga dapat berfungsi sebagai titik awal untuk analisis dinamis lain yang lebih rinci, seperti

respons harmonik atau analisis dinamis transien penuh. Analisis modal, sementara menjadi

salah satu jenis analisis dinamis paling dasar yang tersedia di ANSYS, juga dapat lebih

memakan waktu komputasi daripada analisis statis biasa. Pada penelitian ini massa titik sekitar

250 kg dilakukan dengan menggunakan Analisis Modal ANSYS 19.1 Workench [3][10].

Gambar 2.8. Modal Analysis

Tabel 2.8 Result Modal Analysisi Revolution 5 mm (AISI 347)

No Mode Frequency (Hertz) Total Deformation (mm)

1 1 0.63093 1.3092

2 2 0.63361 1.3078

3 3 23.798 77.165

4 4 23.871 76.621

5 5 37.094 72.607

6 6 41.483 77.267

Tabel 2.9 Result Modal Analysisi Revolution 5 mm (ASTM A228)


1 1 0.59935 1.3068

2 2 0.6011 1.3087

3 3 24.002 77.153

4 4 24.082 76.624

5 5 37.27 72.597

6 6 42.001 77.232

9

Gambar 2.9 Total Deformation AISI 347 (Revolution, 5 mm)

10

Dari hasil Analisis Modal yang ditunjukkan pada Tabel 3.8-3.9 dan Gambar 3.9-3.10,

dapat dilihat bahwa desain shock absorber yang terbuat dari ASTM A228 dan AISI 9255 aman

untuk mode 1 dan mode 2. Berbeda dengan kasus analisis modal, Shock absorber yang terbuat

dari kedua material tersebut memiliki hasil yang berbeda. Hal ini menunjukkan bahwa peredam

kejut diperkirakan aman terhadap analisis modal mode 1-2 tetapi mungkin gagal dalam analisis

modal untuk mode 3-6.

Berdasarkan hasil analisis struktural, faktor keamanan untuk umur kelelahan telah

dihitung. Perhitungan fatigue telah dilakukan untuk material ASTM A231 dan AISI 9255

berdasarkan teori fatigue Goodman, Soderberg, dan Gerber. FEA dalam studi ini menunjukkan

bahwa semua desain shock absorber baru aman terhadap pembebanan statis. Berdasarkan

analisis modal, desain peredam kejut diperkirakan aman dalam mode analisis modal 1-2 tetapi

mungkin gagal dalam mode analisis modal 3-6. Desain shock absorber terbaik untuk under

static loading adalah desain shock absorber baru berdiameter 6 mm dan model revolution pegas

berbahan AISI 9255 karena desain ini lebih ringan dari model pitch [11]

PROSES PEMBUATAN PRODUK DENGAN METODE INVESMENT CASTING

Pembutan produk shock absorber menggunakan proses pengecoran logam metode

Invesment Casting dan metode rolling. Shock absorber ini memiliki 3 komponen utama yaitu

komponen atas, komponen bawah dan komponen spring. Semua komponen diproduksi

menggunakan metode investment casting kecuali komponen spring dibuat dengan

menggunkan metode rolling. Pembuatan prototipe Shock Absorber dilakukan di PT. Pelopor

Teknologi Implantindo, Mojokerto, Jawa Timur.

Tahapan awal penelitian adalah karakterisasi material dan pembuatan desain yang

digunakan untuk proses simulasi. Karakterisasi material yang pertama yang dilakukan adalah

uji komposisi dan thermal analysis berupa pengujian Spektro, DSC dan TGA. Pengujian ini

dilakukan untuk mengetahui komposisi kimia, specific heat capacity dan melting point dari

material tersebut. Proses selanjutnya yaitu pembuatan desain Shock Breaker menggunakan

Gambar 2.10 Total Deformation ASTM A228 (Revolution, 5 mm)

11

bantuan software CAD berupa Solidwork 2014. Kemudian file disimpan dalam bentuk ekstensi

Parasolid yang nantinya akan diimport di FEA software.

Gambar 2.11 Geometri dan desain Shock Absorber

Setelah pembuatan desain Shock Breaker selesai maka sebelum proses manufacturing

terlebih dahulu dilakukan proses simulasi menggunakan software ANSYS 2019. Analisis ini

digunakan untuk mensimulasikan fenomena apa saja yang akan terjadi pada saat pembuatan .

Sehingga dengan analisis ini akan menekan terjadinya kecacatan produk. Shock Breaker

dimodelkan menggunakan modul analisis thermal transient untuk mengetahui distribusi

temperature. Kemudian dilanjutkan menggunakan modul transient static tructural untuk

mengetahui deformasinya [10].

Permodelan pertama dilakukan dengan menggunakan analisa transient thermal untuk

mengetahui distribusi temperatur. Selanjutnya, dilakukan analisa couple-field dengan transient

structural. Analisa coupled-field dapat merepresentasikan efek termal untuk dikaitkan pada

fenomena lain. Analisa transient structural kemudian dilakukan untuk mengetahui tegangan

termal dan shrinkage yang terjadi pada produk hasil pengecoran. Analisa termal pada

permodelan ini menggunakan program Ansys Workbench 19.1 dengan modul transient

thermal. Analisa transient thermal menentukan temperatur dan besaran termal lain yang

berubah terhadap waktu. Sebuah analisa transient thermal pada dasarnya memiliki prosedur

yang sama dengan analisa steady-state thermal, perbedaan utama diantara keduanya adalah

sebagian besar pembebanan pada analisa transient adalah fungsi terhadap waktu. Tabel

dibawah ini menunjukkan beberapa sifat dari material yang harus dimasukkan ke dalam

permodelan untuk mendapatkan output yang diinginkan [12][13][14]

12

Tabel 2.10 Input dan output pada Analisa permodelan

Analisa Modul Input Output

Termal Transient

Thermal

Konduktivitas termal,

koefisien panas spesifik,

densitas

Distribusi

temperatur

Struktural Transient

Structural

Modulus elastisitas,

poisson ratio, koefisien

ekspansi termal

Tegangan termal,

shrinkage

Analisa termal yang pertama adalah analisa mengenai distribusi temperatur pada

material pengecoran. Shrinkage merupakan peristiwa menyusutnya volume selama proses

pengecoran setelah dilakukan pendinginan. Untuk menghitung shrinkage yang terjadi selama

simulasi, diperlukan nilai deformasi pada hasil pengecoran di setiap sumbu. Selanjutnya,

geometri awal produk dikurangi dengan deformasi tersebut sehingga didapatkan volume akhir

produk. Dengan mengurangkan volume awal dengan volume akhir, maka didapatkan besarnya

shrinkage pada produk pengecoran. Apabila hasil analisa ANSYS sudah menunjukkan hasil

yang seperti apa yang dinginkan maka proses selanjutnya berupa Investment Casting dan Hot

Working. Apabil hasil dari simulasi ANSYS belum sesuai maka akan dilakukan desain model

ulang menggunakan Solidwork [10].

Apabila hasil analisa ANSYS sudah menunjukkan hasil yang seperti apa yang

dinginkan maka proses selanjutnya berupa pengecoran dengan metode investment casting

dengan bahan logam. Untuk pembuatan komponen Spring mengunakan metode Hot Working.

Untuk kegiatan pengecoran dengan metode investment casting dilakukan di PT. Pelopor

Teknologi Implantindo, Mojokerto, Jawa Timur.

13

Gambar 2.12 Komponen yang akan dilakukan Investment Casting

Gambar 2.13 Komponen yang akan dilakukan Hot Rolling

14

Gambar 2.14 Hasil Simulasi Casting dengan menggunakan Software ANSYS 19.1

15

Gambar 2.15 Hasil dari Investment Casting dan Rolling

Gambar 2.16 Prototipe Produk Shock Absorber

16

BAB III STATUS LUARAN Penelitian ini telah memiliki luaran berupa:

1. International Conference

Penelitian ini telah diikutkan pada acara International Meeting on Advances in Materials

(i-MAM) 2020 yang diadakan oleh Departemen Teknik Metalurgi dan Material, Fakultas

Teknik, di Universitas Indonesia yang telah dipresentasikan pada tanggal 16-17 Nopember

2020. Paper yang akan dipresentasikan berjudul “Design and Analysis of Shock Absorber

Using ANSYS”. Selain itu paper dengan judul “The Finite Element Analysis and The

Optimization Design of Shock Absorber Based on ANSYS” juga telah presentasikan pada

acara “The 4th International Conference on Materials and Metallurgical Engineering and

Technology (ICOMMET) 2020” yang akan dipresentasikan pada tanggal 19-20 Oktober 2020.

2. Hak Paten Sederhana

Penelitian ini telah menghasilkan suatu desain imlan tulang pinggul (artificial hip joint),

kemudian desain ini telah didaftarkan Hak Paten. Untuk progress kemajuan dan pengurusan

hak paten telah sampai proses pendaftaran oleh pihak LPPM ITS.

3. Jurnal Internasional

Penelitian ini akan di submit ke Jurnal International terindeks Scopus (Minimal Q2), untuk

proses kemajuan dari pembautan Jurnal Internasional ini telah sampai tahap submitted pada

jurnal Materials and Design.

Selain luaran diatas, penelitian ini juga menghasilkan luaran beruapa beberapa desain baru

dari shock absorber bagi PT. Pelopor Teknologi Implantindo yang nantinya akan dapat

diproduksi untuk memenuhi kebutuhan komponen shock absorber untuk motor elektrik

17

BAB IV PERAN MITRA

Pada penelitian ini dilakukan dengan bantuan mitra yaitu PT. Pelopor Teknologi

Implantindo Mojokerto. Mitra tersebut dalam penelitian ini memiliki beberapa peran dan tugas

antara lain:

1. Melakukan pengujian awal dari material bahan baku

2. Melakukan desain Shock Absorber

3. Melakukan pengecoran Shock Abosrber dari desain yang telah dilakukan simulasi

dengan ANSYS

4. Melakukan pengujian komposisi dari produk Shock Absorber hasil investment casting

18

BAB V KENDALA PELAKSANAAN PENELITIAN Kendala yang dialami pada saat penelitian adalah keterbatasan perangkat computer

untuk dapat melakukan simulasi dengan software ANSYS 19.1 dan karena pandemi COVID

19 maka akses untuk melakukan penelitian di laboratorium di ITS sangat terbatas. Selain itu

kendala yang dialami adalah pembelian bahan baku untuk produksi shock absorber yang

relative sulit pada proses pengiriman karen adanya pandemi COVID 19.

19

BAB VI RENCANA TAHAPAN SELANJUTNYA Rencana tahapan dari penelitian ini adalah melakukan uji coba dengan cara

pemasangan produk shock absorber ini pada motor GESITS. Hal ini dilakukan untuk

memastikan kemampuan dan kekuatan dari produk shock absorber ini apabila mengalami

pembebanan sebenarnya. Setelah melakukan pengujian pada motor GESITS tahap selanjutnya

adalah proses produksi secara massa produk shock absorber ini. Dalam hal ini akan

mengganteng mitra terkait yaitu PT. WIKA.

v

BAB VII DAFTAR PUSTAKA

[1] Rogerz, Kara.2011. Bone and Muscle Structure, Force and Motion. Britannica

Educational Publishing. New York

[2] www.Kemenkes.go.id

[3] World Health Organization FRAX, Calculation, 2011

[4] Colic, K. 2016. The Current Approach to Research and Design of The Artificial

Hip Prothesis. University of Berlgarde, Innovation Center. Serbia

[5] Smallman. & A.H.W. Ngan, 2007. Physical Metallurgy and Advanced Material,

Sevent Edition. Elsevier Science and Sabre Foundation Book

[6] Iyer, Mohan. 2018, The Hip Joint in Adults Advance and Developments, Pan

Stanford Publishing Pte. Ltd. Singapore

[7] Hasirci, Vasif. 2018. Fundamentals of Biomaterials, Springer Science. New York

[8] Buddy D, Ratner. 2013. Biomaterials Science an Introduction to Materials in

Medicine. Third Edition, Elsevier Science and Sabre Foundation Book.

[9] Park, John and Lakes. 2007. Biomaterials in Introduction. Third edition. Vol 1.USA

CRC Press

[10] Xiaolin. 2019. Finite Element Modelling and Simullation with ANSYS Workbench.CRC Press.

London

[11] Campbell. 2015. Complete Casting Handbook.Elsevier.Ltd.USA

[12] Carmen. 2019. Support Vector Representation Machine for Superalloy Investment

Casting Optimization. Department of Engineering and Architecture, University of

Trieste. Italy

[13] Nabakumar, Pramanik, Mishra, Indranil, Tapas Kumar, Parag Bhargava. 2009.

Chemical Synthesis, Characterization, and Biocompatibility Study of

Hidroxyapatite/Chitosan Phosphate Nanocomposite for Bone Tissue Engineering

Application. International Journal of Biomaterials. Volume Article ID 512417

[14] Yildrim, Oktay. 2004. Preparation and Characterization of Chitosan/Calsium

Phosphate Bases Composite, Turkey.

vi

BAB VIII LAMPIRAN

Lampiran 1. Tabel Daftar Luaran

TABEL DAFTAR LUARAN

Program : Penelitian Prototipr

Nama Ketua : Yuli Setiyorini, S.T., MPhil., Ph.D Eng.

Judul : Prototipe Pembuatan Shock Absorber Untuk Motor Listrik (Gesits)

Dalam Rangka Meningkatkan TKDN

1. Artikel Jurnal

No Judul Artikel Nama Jurnal Status Kemajuan

1

Design and And Analysis of New

Shcok Absorber Design Using

ANSYS

Material and

Design (Q1)

Akan disubmit

bulan desember

2020

2. Artikel Konferensi

No Judul Artikel

Detail Konferensi

(Nama

Penyelenggara,

tempat, tanggal)

Status Kemajuan

1

The Finite Element Analysis and

The Optimization Design of Shock

Absorber Based on ANSYS

Departemen Teknik

Material dan

Metalurgi, ITS

Surabaya. 19-20

Oktober 2020

Accepted and

Presented

2 Design and Analysis of Shock

Absorber Using ANSYS

Departemen Teknik

Metalurgi dan

Material, Fakultas

Teknik, Universitas

Indonesia, 16 -17

Nopember 2020

Accepted and

Presented

3. Paten

No Judul Usulan Status Kemajuan

1 Desain Shock Absorber Untuk Motor

Elektrik

Telah dilakukan pendaftaran HKI oleh

LPPM ITS

vii

Lampiran 2. Bukti Accepted dari International Meeting on Advances in Materials

(i-MAMM) 2020, Universitas Indonesia

Lampiran 3. Bukti Accepted dari International Conference on Materials and Metallurgical

Engineering and Technology (ICOMMET) 2020, ITS

viii

Lampiran 3. Bukti Accepted ICOMMET 2020 (ITS SURABAYA)

ix

Ringkasan penelitian berisi latar belakang penelitian,tujuan dan tahapan metode peneliti

Lampiran 4. Bukti Conference di ICOMMET 2020 (ITS SURABAYA)

x

Lampiran 5. Draft HKI

Deskripsi

DESAIN SHOCK ABSORBER UNTUK MOTOR ELEKTRIK

Bidang Teknik Invensi

Invensi ini berkaitan dengan metode proses pembuatan shock

absorber cakupannya berupa penentuan desain komponen shock absorber

berbahan dasar ASTM A228, sebagai salah satu komponen dalam

kendaraan bermotor. Lebih khusus lagi, invensi ini berhubungan

dengan modifikasi pada model dan ukuran diameter spring dan

modifikasi bentuk dan ukuran pada komponen shock absorber.

Latar Belakang Invensi

Shock absorber adalah komponen penting dalam sistem suspensi

suatu kendaraan, yang berguna untuk meredam gaya osilasi dari pegas.

Shock absorber berfungsi untuk memperlambat dan mengurangi besarnya

getaran gerakan dengan mengubah energi kinetik dari gerakan

suspensi menjadi energi panas yang dapat dihamburkan melalui cairan

hidrolik. Peredam kejut (shock absorber) pada motor memiliki

komponen pada bagian atasnya terhubung dengan piston dan

dipasangkan dengan rangka kendaraan. Bagian bawahnya, terpasang

dengan silinder bagian bawah yang dipasangkan dengan as roda. Fluida

kental menyebabkan gaya redaman yang bergantung pada kecepatan

relatif dari kedua ujung unit tersebut. Hal ini membantu untuk

mengendalikan guncangan pada roda. Shock absorber bekerja dalam dua

siklus yakni siklus kompresi dan siklus ekstensi.

Struktur atau komponen pembentuk shock absorber bermacam-macam

berdasarkan sistem kerja dan jenisnya. Konstruksi shock absorber

itu terdiri atas piston, piston rod dan tabung. Piston adalah

komponen dalam tabung shock absorber yang bergerak naik turun di

saat shock absorber bekerja. Sedangkan tabung adalah tempat dari

minyak shock absorber dan sekaligus ruang untuk piston bergerak

naik turun. Piston rod adalah batang yang menghubungkan piston

xi

dengan tabung bagian atas (tabung luar) dari shock absorber. Ada

komponen yang terbuat dari logam namun ada juga komponen yang

terbuat dari polimer maupun komposit.

Invensi teknologi yang berkaitan dengan proses pembuatan shock

absorber sebelumnya dikemukakan John T. Thompson pada Paten United

States No CN 4036335 pada 19 Juli 1977 berjudul: Adjustable Shock

Absorber. Paten tersebut mengklaim desain shock absorber dengan

penambahan komponen pada bagian luar akan mampu menigkatkan

kualitas berkendara karena dengan penambahan alat ini dapat

mengontrol tingkat kekerasan dari spring pada shock absorber.

Invensi teknologi yang berkaitan dengan metode pembuatan shock

absorber juga telah diungkapkan oleh Nishikawa et al. sebagaimana

terdapat pada paten United States Nomor 4183509 tanggal 15 Januari

1980 dengan judul: Shock Absorber for Vehicle Use. dimana

diungkapkan bahwa penambahan komponen piringan orifice dengan

berbagai ukuran pada sistem suspensi akan dapat mengontrol

mekanisme spring, sehingga tingkat kenyamanan spring dan shock

absorber dapat diatur sesuai keinginan pengendara. Namun kedua

invensi tersebut masih terdapat kekurangan yaitu komponen shock

absorber yang digunakan kompleks dan banyak sehingga akan

meningkatkan kemungkinan kerusakan pada saat pemakaian. Selain itu

dengan banyaknya komponen penyususn shock absorber akan

meningkatkan massa total dari shock absorber tersebut.

Selanjutnya Invensi yang diajukan ini dimaksudkan untuk

mengatasi permasalahan yang dikemukakan diatas dengan cara

melakukan desain ulang pada komponen shock absorber. Invensi yang

diajukan ini menghasilkan suatu produk shock absorber dengan massa

yang lebih ringan dan kemampuan mekanik yang baik.

Uraian Singkat Invensi

Tujuan utama dari invensi ini adalah untuk mengatasi

permasalahan yang telah ada sebelumnya khususnya dalam memperoleh

produk shock absorber sepeda motor elektrik dengan kemampuan yang

baik, ringan dan memiliki umur pakai yang panjang. Kemampuan suatu

shock absorber sangat bergantung pada desain dan bahan baku dari

xii

tiap komponennya, sesuai dengan invensi ini terdiri dari 3 bagian

shock absorber yaitu bagian atas, bagian bawah dan bagian spring.

Pada bagian spring akan dibuat desain spring dengan model revolution

dengan diameter 5 mm. Tujuan lain dari invensi ini adalah untuk

dapat memproduksi shock absorber dengan desain sederhana, berat

yang ringan dan kemampuan mekanik yang baik sehingga dapat

diaplikasikan untuk motor listrik.

Uraian Singkat Gambar

Gambar 1, adalah bentuk desain dari shock absorber sepeda motor

elektrik

Gambar 2, adalah bentuk desain bagian spring dari shock absorer

sepeda motor elektrik

Gambar 3, adalah bentuk desain bagian bawah dari shock absorber


Gambar 4, adalah bentuk desain bagian atas dari shock absorber


Gambar 5, adalah distribusi tegangan pada shock absorber hasil

simulasi dengan software komputer

Gambar 6, adalah distribusi deformasi pada shock absorber hasil

simulasi modal dengan berbagai mode

Uraian Lengkap Invensi

Invensi ini akan secara lengkap diuraikan dengan mengacu

kepada gambar-gambar yang menyertainya. Proses pembuatan shock

absorber dapat dilakukan dengan cara pengecoran logam dengan desain

yang telah ditentukan kemudian dilakukan perakitan.

Invensi ini berisikan tentang desain untuk shock absorber

dengan model spring berupa revolution dengan diamter spring sebesar

5 mm. Shock absorber didesain memiliki bentuk spring berupa

revolution yang bertujuan untuk mengurangi massa atau beban dari

spring tersebut namun tetap memiliki kemampuan yang optimal. Bentuk

revolution juga dapat menahan dan menyebarkan tegangan yang dialami

spring dengan baik.

xiii

Mengacu pada Gambar 1, yang memperlihatkan gambar utuh hasil

perakitan dari 3 komponen utama penyusun shock absorber yaitu bagian

atas , bagian bawah dan bagian spring.

Mengacu pada Gambar 2, menunjukkan bentuk dan ukuran dari

komponen spring. Mengacu pada Gambar 2, memperlihatkan bahwa pada

desain shock absorber memeiliki diameter sebesar 5 mm.

Mengacu pada Gambar 3, menunjukkan bentuk dari bagian bawah

komponen shock absorber. Pada Gambar 4, merupakan desain bagian

atas dari komponen shock absorber.

Mengacu pada Gambar 5, menunjukkan distribusi tegangan pada

desain shock absorber. Dari hasil simulasi dapat dilihat bahwa

tegangan maksimal yang dihasilkan oleh desain masih dibawah dari

batas luluh dari material bahan baku pembuatnya. Berdasarkan hasil

simulasi ini dapat disimpulkan bahwa desain shock absorber akan

aman jika dikenai beban.

Mengacu pada Gambar 6, menunjukkan distribusi total deformasi

pada desain shock absorber. Dari hasil simulasi dapat dilihat bahwa

desain shock absorber akan aman pada saat dikenai beban 250 kg

untuk analisa modal.

Dari desain shock absorber hanya terdiri dari 3 komponen utama,

hal ini dilakukan untuk menurunkan massa dari shock absorber

tersebut. Dari uraian diatas jelas bahwa hasil dari invensi ini

adalah produk shock absorber dengan keterangan seperti berikut

Total Deformation : 23,25 mm

Equivalent Von Misses Stress

Maximum : 143,95 Mpa

Minimum :0,02691 Mpa

Maximum Principal Stress :87,617 Mpa

Maximum Equivalent elastic strain :0,00081906 Mpa

Maximum principal elastic strain :0,00047582 Mpa

Safety Factor

Metode Goodman :2,780242

Metde Soderberg :2,195982

Metode Gerber :3,437771

xiv

Berat Spring :406,46 gram

Simulasi Modal

Tabel 1. Hasil Modal Analisis

No Mode Frekuensi (Hertz) Total deformasi (mm)

1 1 0,59935 1,3068

2 2 0,6011 1,3087

xv

Klaim

1. Metode pembuatan shock absorber berbahan dasar ASTM A228 dengan

desain shock absorber seperti pada gambar yang telah

dilampirkan.

2. Metode pembuatan shock absorber berbahan dasar ASTM A228 sesuai

klaim 1 dapat menghasilkan produk spring untuk shock absorber

dengan berat 406,46 gram.

3. Metode pembuatan shock absorber berbahan dasar ASMT A228 sesuai

klaim 2 akan menghasilkan produk shock absorber dengan kekuatan

mekanik dan nilai safety factor yang baik.

xvi

Abstrak

DESAIN SHOCK ABOSRBER UNTUK MOTOR ELEKTRIK

Invensi ini berkaitan dengan metode proses pembuatan shock

absorber cakupannya berupa penentuan desain komponen shock absorber

berbahan dasar ASTM A228, sebagai salah satu komponen dalam

kendaraan bermotor. Lebih khusus lagi, invensi ini berhubungan

dengan modifikasi pada model dan ukuran diameter spring dan

modifikasi bentuk dan ukuran pada komponen shock absorber. Tujuan

utama dari invensi ini adalah untuk mengatasi permasalahan yang

telah ada sebelumnya khususnya dalam memperoleh produk shock

absorber sepeda motor dengan kemampuan yang baik, ringan dan

memiliki umur pakai yang panjang. Kemampuan suatu produk shock

absorber sangat bergantung pada desain dan bahan baku dari tiap

komponennya. Pada invensi ini komponen shock absorber terdiri dari

3 bagian utama yaitu bagian atas, bagain bawah dan bagian spring.

Pada bagian spring ini akan dibuat desain spring dengan model

revolution dengan diameter 5 mm. Tujuan lain dari invensi ini adalah

untuk dapat memproduksi shock absorber dengan desain sederhana,

massa yang ringan dan kemampuan mekanik yang baik sehingga dapat

diaplikasikan untuk motor elektrik.

xvii

Gambar 1.

xviii

Gambar 2.

Gambar 3.

xix

Gambar 4.

Gambar 5.

xx

Lampiran 6. Draft Paper untuk ICOMMET 2020 ITS Surabaya

The Finite Element Analysis and The Optimization Design of

Shock Absorber Based on ANSYS

Yuli Setiyorini1, a), Sungging Pintowantoro1, b), Anni Rahmat2,c), Fahny Ardian 1,d)

1Material Department, Sepuluh Nopember Institute of Technology, Surabaya, East Java, Indonesia 60111 2 Chemical Engineering Department, Semen Indonesia International University, Gresik, East Java, Indonesia 61122

Corresponding author: a) [email protected] b) [email protected]

c) [email protected] d) [email protected]

Abstract. The shock absorber is a part designed to smooth out the shock impulse and dissipate kinetic energy. The engine

is the main power of the vehicle and the most direct reason that cause the vibration of the vehicle. If the shock absorber

cannot control the vibration will make other parts of the body has seriously affect like vehicle handling stability and shorten

the vehicle's component life. The shock absorber system connects a vehicle to its wheels and contributes to the vehicle’s

road handling and braking for better safety and driving pleasure and offering a comfortable ride well isolated from road

noise, bumps, vibrations. In this paper, the authors propose a new shock absorber design that it can smooth out or damp

shock impulse, dissipate kinetic energy, and reduced amplitude of disturbances. When a vehicle is through on a level road

and the wheels strike a bump, the spring is compressed. The compressed spring will attempt to return to its normal loaded

length and will rebound past its normal height, causing the passenger and body vehicle to be lifted. The rebound process is

repeated over and over, a little less each time, until the up-and-down movement finally stops. The design of spring in the

shock absorber system is very urgent. In this project, a shock absorber is created using SolidWorks 2014. The model is also

varying diameter and design of the spring. Structural analysis and modal analysis are done on the shock absorber by varying

material for AISI 347 and ASTM A228 using ANSYS 19.1. The analysis is done by considering loads, bike weight with 2

person passengers. Static structural analysis was done to validate the strength of the materials and design. Modal analysis

was done to know the displacements for different frequencies for the number of modes. Comparison is done for two materials

with a varying diameter of spring to verify the best materials and design for the shock absorber. Based on the static analysis

result, the safety factor for the fatigue life of the shock absorber design has been calculated based on Goodman, Soderberg,

and Gerber fatigue theories. The stresses and strains were also found to be optimum which leads to increase of structural

strength of the shock absorber.

Keyword(s): Shock Absorber, Material, Spring, Designn, FEA

INTRODUCTION

The shock absorber system has used widely in different fields, such as civil, aerospace and automotive

engineering, for vibration absorption and system stability [1][2]. The shock absorber is a mechanical component of

vehicle that function to reduce the vibrations. The shock absorber includes spring, valves and orifices used to manage

the flow of oil and gasses through an internal piston. The shock absorbers minimize the effect of traveling over rough

ground, leading to improved ride quality and vehicle handling. The shock absorbers in motorcyle use valving of oil or

gas to absorb excess energy from the springs cause by traveling. Spring was chosen by the factory based on the weight

of the vehicle (loaded and unloaded). During hysteresis in the tire, they damp the energy stored in the motion of the

unsprung weight up and down. Effective of wheel motorcycle bounce damping may require tuning shocks to an optimal

resistance [3][4][5][6]. Spring of the shock absorbers in motorcycle commonly use coil springs. Motorcycle usually

employ both hydraulic shock absorbers and springs. In this combination, shock absorber refers specifically to the

hydraulic piston that absorbs and dissipates vibration and energy [7].

Hydraulic and pneumatic shock absorbers usually take the form of a cylinder with a sliding piston inside. The

cylinder is filled with a fluid or gas. This fluid-filled piston/cylinder combination is a dashpot. One of design decision,

when designing or choosing the shock absorber, is where that energy will release [8]. In most shock absorber, the excess

energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid will heat up, while in gas

mailto:[email protected]




xxi

cylinders, the hot gasses will exhaust to the atmosphere or environment. In general, the shock absorbers help cushion

vehicle on uneven tracks [9]

Finite Element Analysis (FEA) is a computer-based numerical methode to calculate the phenomena and

behavior of engineering structures. It can be used to determine stress, strain, deformation, safety factor, vibration,

buckling behavior and other phenomena. It can be used to calculate either small or large-scale deformation under

loading or unloading. It can analyze elastic deformation or plastic deformation. This technique is also distinguished

from finite differential equations, for which although the steps into which space is divided are finite in size, there is

little freedom in the shapes that the discreet steps can take. FEA is a way to deal with structures that are more complex

than can be dealt with analytically using partial differential equations. FEA deals with complex boundaries better than

finite difference equations and gives answers to structural problems [1][10][11].

In FEA, the actual continuum or body of matter like solid, liquid or gas is represented as an assemblage of

subdivisions called finite elements. These elements are considered to be interconnected at specified joints called nodes

or Nodal points. The nodes usually lie on the element boundaries where adjacent elements are considered to be

connected since actual variation of the field variable inside a finite variable inside a finite element can be approximated

by a function. These approximate functions are defined in terms of the value of the field’s variables at the nodes. A

static structural analysis determines the stresses, strains, and deformation in structures or components caused by loads

that do not induce significant inertia and damping effects. Steady loading and transient loading response conditions are

assumed; that is, the loads and the structure's response and phenomena are assumed to vary slowly with respect to time

[2][11].

The research about shock absorber simulation has been done, A. Chinnamahammad bhasha, N. Vijay rami

reddy, B. Rajnaveen, worked on suspension system also created and a 3D model is generat using CATIA V5 R21. The

project used spring steel, phosphor bronze, berilium copper and titanium alloy as spring material. They considered

weight of bike with double riding. Final comparison is done for different materials to calculated best material for spring

in the shock absorber. Modeling is done in CATIA and analysis is done in ANSYS [12]. Syambabu Nutalapati, in the

research a shock absorber designed and a 3D model is created using CATIA. Static structural and modal analysis are

done on the shock absorber by varying material for Spring Steel and Molybdenum [1]. Pinjarla Poornamohan,

Lakshmana Kishore, In their project a shock absorber is designed and a 3D model is created using Pro/Engineer. The

size of spring is varied and the material is spring steel and beryllium copper. Structural analysis is done to verify the

displacement at number of nodes at different frequencies using Ansys [13]. Rahul Tekade, Chinmay Patil, has carried

Structural and Modal Analysis of Shock Absorber of Vehicle to sustain more vibrations at all conditions [14].

METHODOLOGY

In this project a new design of shock absorber has been simulated to consider safety factor to estimate the

properness of the shock absorber. Finite element model of the shock absorber was generated in SolidWorks 2014. The

model of shock absorber was imported in ANSYS 19.1 for analysis. Static structural analysis and modal analysis was

performed applying average two passangers and stress distribution, total deformation and safety factor was calculated.

Maximal and minimal stress (von misses) variation with respect to time was recorded. Maximal and minimal stress

variation were used to determine safety factor and properness of the shock absorber. The purpose of a novel design for

a shock absorber was obtained light, reliable, good and durable design [15]. The purpose of making this new design is

to produce a shock absorber design with the ability to have the maximum capability with the lightest weight. The model

spring influenced the ability of shock absorber. The shock absorber design has to reduce the stress distribution during

loading and unloading, perhaps will increase the lifetime and properness of the shock absorber [16]. With the variety

of spring model and diameter in the shock absorber is expected to reduce the weight and distribute the stress of the

shock absorber shown in Figure 1-3 and Table 1.

xxii

Figure 1. Top and Bottom Part of The Shock Absorber

Figure 2. Spring Part of Shock Absorber (a) Pitch Model (b) Revolution Model

FINITE ELEMENT ANALYSIS

Static structural and modal analysis of shock absorber have to conducted to ensure about the safety factor and

properness of the shock absorber design [11]. In the literature, shock absorber is often designed according to the result

of static structural and modal analysis. Static structural and modal analysis is mostly conducted under weight of vehicle

and two passangers [1]. The simulation of the shock absorber which must be taken into account not to cause fracture of

fatigue failure of the shock absorber .To calculate how static structural and modal analysis result differ from each other

design of shock absorber, with varying the materials, model and diameter of the spring. Material properties of the shock

absorber could be seen in Table 2.

a

b

xxiii

Figure 3. Design of Shock Absorber

Table 1. Research Parameters

\

Table 2. Materials Properties [17]

RESULT AND DISCUSSION

FEA of shock absorber are carried out using ANSYS 19.1. It is important that the maximum equivalent stress

on the shock absorber have to lower than the yield strength of the materials. In the static structural analysis, stresses

were always lower than the respective material strengths. Maximum Von Misses stresses in the shock absorber designs

resulted from static structural analyses are shown in Figure 4-7. It is important that the maximum equivalent stress on

the shock absorber should be lower than the endurance limit of the materials for safety. The calculated Von Misses

stress as shown in table are much lower than yield stress of AISI 347 and ASTM 228 given in Table 3-4. This mean all

shock absorber design made of AISI 347 and ASTM A228 is safe because the maximum von misses stress in lower

than the yield point of materials. Design with 5 mm diameter and revolution model made of ASTM 228 is the best

design for under static structural analysis.


AISI 347

Pitch

5

7

9

Revolution

5

7

9

ASTM A228

Pitch

5

7

9

Revolution

5

7

9


(GPa) Possion Ratio

Yield Strength

(MPa)

UTS

(MPa)

Density

(gr/cm3)

ASTM 40 180 0,29 200 310 7,5

AISI 347 195 0,27 450 690 7,93

ASTM A228 200 0,29 350 650 7,8

xxiv

Table 3. Maximum Von Mises Stress of shock absorber made from AISI A228 + ASTM 40

Tabel 4. Maximum Von Mises Stress of shock absorber made from AISI 347 + ASTM 40

Materials Spring Model Diameter of

Spring (mm)

Maximum Von

Misses Stress

(MPa)

Maximum Von

Misses Stress

(MPa)

Total

Deformation

(mm)

ASTM 228

&

ASTM 40

Pitch

5 145,12 0,019418 23,264

7 162,86 0,014267 22,822

9 221,08 0,0071345 21,94

Revolution

5 143,95 0,021644 23,25

7 181,77 0,021644 22,81

9 231,38 0,0044108 21,742


Spring (mm)

Maximum Von

Misses Stress

(MPa)

Maximum Von

Misses Stress

(MPa)

Total

Deformation

(mm)

AISI 347

&

ASTM 40

Pitch

5 145,13 0,020342 23,266

7 161,28 0,01298 22,828

9 218,46 0,0064006 21,952

Revolution

5 143,98 0,027197 23,252

7 179,99 0,028123 22,815

9 229,21 0,0048745 21,753

Figure 4. Stress Distribution ASTM 228 + ASTM 40 Pitch

Figure 5. Stress Distribution ASTM 228 + ASTM 40 Revolution

5 mm

5 mm 7 mm

7 mm 9 mm

9 mm

xxv

A proper shock absorber design have to satisfy maximum or an infinite fatigue life. It can be ensured by

physical testing or a fatigue analysis. In this study, fatigue life of the shock absorber upon finite element stress analysis

is predicted using the computer code of ANSYS Workbench. Fatigue calculations of the shock absorber are conducted

for AISI 347 and ASTM A228 materials. Fatigue life of shock absorber is calculated based on Goodman, Soderberg,

Gerber and mean stress fatigue theories. This approach is useful for the initial process of materials selection of shock

absorber materials that will be subjected to high cyclic loading conditions. The advantage of this approach is that it

represents both initiation and propagation of cracks in the aggressive environment. In Table 5, N indicates safety factor

for fatigue life in loading cycle, Se for endurance limit and Su for ultimate tensile strength of the material. Mean stress

𝜎𝑚 and alternating stress 𝜎𝑎 are defined, respectively, as


2 (1)


2 (2)

Table 5. Fatigue analyses were performed according to Goodman, Soderberg and Gerber [18].


Goodman (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑢

) =1

𝑁

Soderberg (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑦

) =1

𝑁


𝑆𝑒

) + (𝑁. 𝜎𝑚

𝑆𝑢

)2

= 1

Figure 6. Stress Distribution AISI 347 + ASTM 40 Pitch

Figure 7. Stress Distribution AISI 347 + ASTM 40 Revolution

5 mm

5 mm

7 mm

7 mm

9 mm

9 mm

xxvi

Table 6. Minimum Safety Factor of Shock Absorber for AISI 347+ASTM 40 material under static loading

Table 7. Minimum Safety Factor of Shock Absorber for ASTM 228+ASTM 40 material under static loading

From Table 6-7, can concluded that all new shock absorber design has different safety factor values according

to all fatigue criteria methods. This means that alll shock absorber designs are safe under static loading is considered.

Among new shock absorber design, shock absorber design with 5 mm dimeter of spring and revolution model made

from ASTM 228 better than the others in fatigue life. Because this design has higher safety factor value in all faigue

theories. The total deformation value of shock absorber was given in Table 3-4.

MODAL ANALYSIS

Modal analysis is the process of determining the inherent dynamic characteristics of a system in forms of

natural frequencies, damping factors and mode shapes, and using them to formulate a mathematical model for its

dynamic behaviour. The formulated mathematical model is referred to as the modal model of the system and the

information for the characteristics are known as its modal data. In this research, point mass about 250 kg carried out

using Modal Analysis ANSYS 19.1 Workench. The model of shock aboseber that used in Modal Analysis show in

Figure 8. The result of modal analysis was given in Figure 9-10 and Table 8-9.

Figure 8. Modal Analysis


Spring (mm) Goodman Soderberg Gerber

AISI 347

&

ASTM 40

Pitch

5 2,951138 2,531972 3,649086

7 2,655561 2,278404 3,283584

9 1,960453 1,682036 2,424074

Revolution

5 2,974764 2,552218 3,678319

7 2,379584 2,041592 2,942363

9 1,868502 1,603146 2,310375



ASTM 228

&

ASTM 40

Pitch

5 2,780242 2,195982 3,437771

7 2,477353 1,95677 3,063233

9 1,82492 1,44146 2,256489

Revolution

5 2,802896 2,213841 3,465802

7 2,219654 1,753207 2,744599

9 1,743661 1,377289 2,156007

xxvii

Table 8. Result Modal Analysisi Revolution 5 mm (AISI 347)


1 1 0.63093 1.3092

2 2 0.63361 1.3078

3 3 23.798 77.165

4 4 23.871 76.621

5 5 37.094 72.607

6 6 41.483 77.267

Table 9. Result Modal Analysisi Revolution 5 mm (ASTM A228)


1 1 0.59935 1.3068

2 2 0.6011 1.3087

3 3 24.002 77.153

4 4 24.082 76.624

5 5 37.27 72.597

6 6 42.001 77.232

Figure 9. Total Deformation AISI 347 (Revolution, 5 mm)

xxviii

From the result of Modal Analysis shown in Table 8-9 and Figure 9-10 can conclude that the design of shock

absorber made of AISI 347 and ASTM A228 were safe for mode 1 and mode 2. Against as in modal analysis case mode

3-6, the shock absorber made of both material has different result. This indicates that the shock absorber predicted to

be safe against mode 1-2 modal analysis but may fail under modal analysis for mode 3-6.

CONCLUSION

The purpose of this research was to determine the properness of shock absorber design based on finite element

analysis. In this research, six different new shock absorber design are created. Shock absorber design have varying

model of spring and varying diameter of spring. The varying model and diameter of spring are designed to reduce

weight of the shock absorber and to know the maximal and minimal distributing stress in the shock abosrber. Static

structural and modal analysis of the shock absorber have been done using ANSYS 19.1. Based on static structural

analysis results, safety factors for fatigue life have been calculated. Fatigue calculations have been carried out for AISI

347 and ASTM A228 materials based on Goodman, Soderberg, and Gerber fatigue theories. Finite element analyses in

this study show that all new shock absorber designs are safe against static loading. Based on modal analysis the shock

absorber design predicted to be safe under modal analysis mode 1-2 but may fail under modal analysis mode 3-6. The

best shock absorber design for under static loading is new shock absorber design with 5 mm diameter and revolution

model of spring made of ASTM A228 material because this design is lighter than pitch model.

Figure 10. Total Deformation ASTM A228 (Revolution, 5 mm)

xxix

ACKNOWLEDGMENTS

This research was supported by internal funding from the Sepuluh Nopember Institut of Technology

REFERENCES

[1] Nutalapati Syambabu. Structural Analysis of Shock Absorber by Using Ansys. Department of Mechanical

Engineering Sasi Institute of Technology & Engineering, Taddepalligudem, Andhara Pradesh, India. (2015)

[2] C. Dixon, John. The Shock Absorber Handbook Second Edition Wiley-PEPublising Serius, UK (2007

[3] W. Shivaraj Sighn, N. Srilatha. Design and Analysis of Shock Absorber: A Review. Mtech Student, VNR VJIET,

Bachupalty, Hyperbad 500090, India

[4] Pinjarla Poornamohan, Lakshmana Kishore T, “Design and Analysis of Shock Absorber,” IJRET, vol. 1, no. 4,

ISSN. 2319-1163,2012. India (2012)

[5] Dheeman Bhuyan, Kaushik Kumar. Computational Fluid Flow Analysis of Base Valve for Twin Tube Shock

Absorbers. Research Scholar, Department of Mechanical Engineering, Birla Institute of Technology, Mesra,

Ranchi 835215, India

[6] R. Bagus Suryasa Majanasastra. Analisis Defleksi dan Tegangan Shock Absorber Roda Belakang Sepeda Motor

Yamaha Jupiter. Program Studi Teknik Mesin, Universitas Islam 45. Indoensia

[7] Suresh Raddy, Thontaraj. Comparative Study of Static Structural Analysis of a Shock Absorber for Different

Materials. Department of Mechanical Engineering, Sri Krishna Institute of Technology, Bangalore – 560090,

Karnataka, India

[8] Achyut P. Banginwar, Nitin D. Bhusale. Design and Analysis of Shock Absorber using FEA Tool. Department

of Mechanical Engineering, Babasaheb Naik College of Engineering, Pusad, (MS) India.

[9] C. Sai Kiran. Design and Analysis of Shock Absorber Using ANSYS Workbench. College of

Engineering/Mechanical Engineering Department, Hyderabad, India

[10] P.R Jadhav, N.P Doshi, U.D Gulhane, “Analysis of Helical Spring in Mono-suspension System used in

Motorcycle,” IJRAT, vol 2, Issue 10,ISSN 2321-9637,Oct,2014.

[11] Xiaolin. Finite Element Modelling and Simulation with ANSYS Workbench. CRC Press, London. (2019)

[12] A. Chinnamahammad Bhasha, N. Vijay Rami Reddy and B. Rajnaveen, “Design and analysis of shock absorber,”

International Journal of Engineering and Technology, vol. 4, Issue 1, pp. 201–207, January 2017

[13] Pinjarla Poornamohan, and T. Lakshmana Kishore, “Design and analysis of shock absorber,” International Journal

of Research in Engineering and Technology, vol. 1, Issue 4, pp. 578–592, December 2012

[14] Rahul Tekade1, Chinmay Patil , “Structural and Modal Analysis of Shock Absorber of Vehicle”,

InternationalJournal of Engineering Trends and Technology (IJETT) – Volume 21 Number 4 – March 2015,

ISSN: 2231-5381, Page 173-186.

[15] Sudarshan Martande,Y.N Jangale,N.S Motgi, “Design and Analysis of shock absorber,” IJAIEM, vol 2, no. 3,

ISSN. 2319-4847. India (2013)

[16] Romualdas Dundulis, Simulation of a shock absorber with vertical buckling tubes welded in the longitudional

direction. Kaunas University of Technology, Lithuania

[17] matweb.com

[18] J.E Shigley and C.R Mischke , Mechanical Engineering Design , McGraw Hill Publication, 5th Edition. 1989.

xxx

Lampiran 7. Draft Paper untuk i-MAMM 2020 Universitas Indonesia

Design and Analysis of Shock Absorber Using ANSYS

Yuli Setiyorini1.b), Sungging Pintowantoro1.c), Fahny Ardian1.c), Anni Rahmat1.d)

1Material Engineering Department, Sepuluh Nopember Institute of Technology, Surabaya,

East Java, Indonesia 60111 2Chemical Engineering Department, Semen Indonesia International University, Gresik,

East Java, Indonesia 61122

Corresponding author: a)[email protected] b) [email protected]

c) [email protected] d) [email protected]

Abstract. The shock absorber is a component that connects a vehicle to its wheels and affected to the

vehicle’s road handling and braking. The shock absorber has to smooth shock impulse and dissipate

kinetic energy. If the shock absorber cannot smooth the disturbance, will shorten the vehicle's

component life. The design of spring and materials selection in the shock absorber are very essentials.

In this paper, a shock absorber was modelled using SolidWorks 2014. The model is also varying

diameter and type of the spring. Structural analysis and modal analysis are done on the shock absorber

using ANSYS 19.1. Structural analysis is done to calculate the mechanical strength and lifetime of

the design and modal analysis is done to determine the deformation for different natural frequencies

for the number of modes. The performance of the new shock absorber designs was investigated for

ASTM A231 and AISI 9255 materials and compared to each other. Based on the static structural

analysis result, the safety factor for the fatigue life of the shock absorber design has been calculated

based on Goodman, Soderberg, and Gerber fatigue theories.

Keywords: Finite Element Analysis, Design, Shock Absorber, Safety Factor, Modal

INTRODUCTION

The shock absorber is a main component of vehicle, aircraft, trains and the supports for many industrial

machines [1]. Shock absorbers have been used in buildings to reduce the probability of structures to earthquake damage.

Shock absorb is a mechanical part designed to smooth out or damp shock impulse and dissipate kinetic energy.

Pneumatic and hydraulic shock absorber generally have form a cylinder with a sliding piston inside. This cylinder

commonly filled with a fluid or air. This fluid-filled piston/cylinder combination is a dashpot [2]. One design

consideration, when designing or choosing a shock absorber, is where that energy will be release. In general dashpots,

energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid will heat up, while in air

cylinders, the hot air is usually exhausted to the e. In general terms, shock absorbers help cushion cars on uneven tracks.

The vehicle without shock absorber probability have problems in handling, as energy which stored in the spring and

then released to the vehicle [3][4].

The spring of shock absorber able to operate in any conditions under a wide range of temperatures. The spring

store energy rather than dissipating it [5]. Metal spring type shock absorbers are used then measures should be provided

to limit oscillations. Metal springs are often used with viscous dampers. There are a number of different types of metal

springs including helical springs, bevel washers(cone-springs), leaf springs, ring springs and etc. Each spring type has

its own operating characteristics [6]. In other hand, the function of shock absorbers is to connect vehicles to its wheels. A shock absorber is coupled

with a spring to convert shock waves into oscillatory motion. The shock absorbers provide a comfortable ride and

stability handling to the vehicle on the uneven track. While a vehicle hits a bump on the track, the spring of the shock

absorber to coil and uncoil. The energy of the spring is moved to the shock absorber through the upper mount, down

through the piston rod and into the piston. The shock absorber works in extension cycle and the compression cycle. In

the extension cycle, the piston moves upwards. In the compression cycle, the piston moves down and compresses the

spring. The compression cycle controls the vehicle’s unsprung weight and extension cycle controls the sprung weight

of the vehicle [7][8][9].





xxxi

Finite Element Analysis (FEA) is a computer-based numerical technique for evaluating the phenomena and

behavior of engineering structures. It can be used to determine deformation, stress, strain, contact pressure, thermal

distribution of engineering design. It can be used to evaluated small or large-scale deflection under loading or applied

forces. The method is also distinguished from finite differential equations, for which although the steps into which space

is divided are finite in size, there is little freedom in the shapes that the discreet steps can take. Finite element analysis

is a way to deal with structures that are more complex than can be dealt with analytically using partial differential

equations. FEA deals with complex boundaries better than finite difference equations and gives answers to structural

problems [10][11].

Bhasha et al. has created a 3D model of shock absorber by using CATIA V5 R21 and changed the size of

spring. A shock absorber minimized the effect of shocks while travelling on uneven tracka and increases the ride comfort

and quality by minimizing the amplitude of shock. Static structural and modal analysis is performed on shock absorber

by considering different materials for spring by using ANSYS. Structural analysis was performed to validate the

strength of the shock absorber. To evaluate the displacements for different frequencies, modal analysis was performed

[12]

Sudarshan et al. has created a new methodology which allows designing the partr of a shock absorber by using

finite element analysis (FEA). In production of shock absorbers, it is difficult to know the accuracy and precision of

shock absorber which doesn’t fail. The shock absorber is generated by using CAD software and analysed in ANSYS

workbench by considering the weight of vehicle. In the results, deflection and stress induced in the shock absorber are

studied [13]

METHODOLOGY

Shape and size of the shock absorber’ component have significant influence on the performance of shock

absorber a during travelling period. The design of shcok absorber must appropriate to the vehicle. In this research a

series of shock absorber design with different model and diameter of spring shown in Figure 1-3 and Table 1. Spring

with different model and diameter generally have different stress concentration and stress distribution and perhaps to

increase lifetime and safety factor of the shock absorber. Spring with large diameter provide maximal stress distribution.

However, it increased the weight of shock abosrber and increase the energy consumption of vehicle. In other hand,

spring with minimum diameter will decrease the weight of shock absorber and increase the possibility of failure caused

by stress concentration and poor stress distribution. Therefore, this research needs to be done in order to obtain an

optimal shock absorber design in terms of weight, comfort during tarveling and good mechanical properties. In this

research, 6 different shock absorber design with varying model and diameter of spring are generated to achieve best

shock absorber design [13]

The important component of a shock absorber are upper mount, piston rod, cylinder and lower mount. All the

different compnent of the shock absorber are cretaed separately in SolidWorks 2014 software and all the individual

parts of the shock absorber are assembled in the SolidWorks 2014. On the lower mount of the shock absorber, a fixed

support is assigned to withstand the forces acting on the shock absorber as shown in Figure 4. Whenever a certain

external load is applied on the upper mount of a shock absorber, the shock absorber cylinder moves down and

compresses the spring. For applying the load on the shock absorber, the weight of the vehicle with two passengers is

calculated.[14][15]

Figure 1. Upper Component of Shock Absorber

xxxii

Figure 2. Bottom Component of Shock Absorber

a

b

Figure 3. Spring Component of Shock Absorber (a) Pitch Spring, (b) Revolution Spring Model

FINITE ELEMENT ANALYSIS

In the present study an attempt has been made to consider safety factor and stress distribution to determine the

useful life of the shock absorber. First a finite element model of the shock absorber was created in SolidWorks 2014.

The developed model was imported in ANYS 19.1 using parasolid extension. Static structural and modal analysis of

shock absorber carried out to evaluated about the safety factor and appropriatennes of the shock absorber model. Static

analysis was performed applying average weight of vehicle and two passanger (7500 N). A CAD model of shock

absorber was created in SolidWorks 2014 as per dimension in Figure 1-3 and saved in Parasolid format, which was

then imprted in ANSYS 19.1 for further simulation [11][16]. The shock absorber were defined with linear elastic

isotropic material. Table 2 shown ASTM A231 and AISI 9255 properties were assigned to the spring of shock absorber

and ASTM 40 were given to the upper and bottom component. Standard surface contact was defined between bottom

and upper component. Coefficient of friction equal to 0.1 was assumed as the component is generally well lubricated

by fluid. The simulation of the shock absorber which must be taken into account not to cause failure of the shock

absorber .To evaluated how static structural and modal analysis result differ from each other design of shock absorber,

with varying the materials, model and diameter of the spring. Finite element analysis of the shock absorber were carried

out using ANSYS 19.1 on a P4 2.0 GHz Intel processor PC[17].

xxxiii

Figure 4. Spring Component of Shock Absorber

Tabel 1. Research Parameter

Table 2. Material Properties

RESULT AND DISCUSSION

FEA of the shock absorber are carried out using ANSYS 19.1. The rules of optimization in this research are to

ensure that the shock absorber design is proper or not. The maximum equivalent stress on the shock absorber should be

lower than the endurance limit of the materials. In addition, the stress on the shock absorber design should be evenly

distributed. The von Mises stress was adopted as the criterion in this work. The von Mises yield criterion is part of a

plasticity theory that applies best to ductile materials, such as metals. Prior to yield, the material response is assumed

to be elastic. In materials science and engineering the von Mises yield criterion can be formulated in terms of the von

Mises stress. The von Mises stress is used to predict yielding of materials under any loading condition from results of

simple uniaxial tensile tests. The von Mises stress has therefore also been widely used in the finite element analysis of

artificial joints. Figure 5-6 shows the von Mises stress on the shock absorber design made of ASTM A231 under static

loading. Figures 6 -7 show the von Mises stress on the shock absorber design made of AISI 9255 under static loading.

The result presented in this study indicated that when a shock absorber is loaded. From the result can concluded that in

shock absorber designm made of ASTM A231 and AISI 9255 is safe because the maximum von misses stress in below

the yield point of materials. In other hand the shock absorber design made of AISI 9255 with revolution model and 6

mm diameter of spring is the best design for under static loading.


ASTM A231

Pitch

6

8

10

Revolution

6

8

10

AISI 9255

Pitch

6

8

10

Revolution

6

8

10


(GPa) Possion Ratio

Yield Strength

(MPa)

UTS

(MPa)

Density

(gr/cm3)

ASTM 40 180 0,29 200 310 7,5

ASTM A231 190 0,29 350 650 7,8

AISI 9255 190 0,28 390 680 7,7

xxxiv

Tabel 3. Maximum Von Mises Stress of shock absorber made from ASTM AA231 + ASTM 40 under static loading

Tabel 4. Maximum Von Mises Stress of shock absorber made from AISI 9255 + ASTM 40 under static loading

Figure 5. Maximum Equivalent Stress of Shock Absorber (Pitch) ASTM A231

Figure 6. Maximum Equivalent Stress of Shock Absorber (Revolution) ASTM A231

Materials Spring

Model

Diameter of

Spring (mm)

Maximum Von

Misses Stress

(MPa)

Maximum Von

Misses Stress

(MPa)

Total

Deformation

(mm)

AISI A231

&

ASTM 40

Pitch

6 145,66 0,031243 23,173

8 184,27 0,0024246 22,539

10 236,02 0,0091344 21,338

Revolution

6 147,68 0,01648 23,135

8 205,81 0,016447 22,476

10 246,08 0,015345 21,172


Spring (mm)

Maximum

Von Misses

Stress (MPa)

Maximum

Von Misses

Stress (MPa)

Total

Deformation

(mm)

ASTM 9255

&

ASTM 40

Pitch

6 145,64 0,031546 23,172

8 185,4 0,0022909 22,534

10 237,49 0,0080 21,326

Revolution

6 148,79 0,016236 23,134

8 207,1 0,016767 22,47

10 247,88 0,013574 21,157

6 mm 8 mm

10 mm

6 mm 8 mm 10 mm

xxxv

Goodman, Soderberg and Gerber theories was used for determining of safety factor of shock absorber designs.

In this research, safety factor of the shock absorber is evaluated using ANSYS Workbench. Safety factor calculations

of the shock absorber are conducted for ASTM A231 and AISI 9255 materials. In the FEA, the materials are considered

to be isotropic elasticity. Therefore, the safety factor was ensured to be more than 1 that conclude the shock absorber

design is safe. The formulation of goodman, soderberg and gerber theories can be seen in Table 5.


2 (1)


2 (2)

N = Safety Factor

Se = Endurance Limit (MPa)

Su = Ultimate Tensile Strength (MPa)

𝜎𝑚 = Mean Stress (MPa)

𝜎𝑎 = Alternating Stress (MPa)

Tabel.5 Fatigue analyses were performed according to Goodman, Soderberg and Gerber methodes.

Figure 7. Maximum Equivalent Stress of Shock Absorber (Pitch) AISI 9255

Figure 8. Maximum Equivalent Stress of Shock Absorber (Revolution) AISI 9255


Goodman (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑢

) =1

𝑁

Soderberg (𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑦

) =1

𝑁


𝑆𝑒

) + (𝑁. 𝜎𝑚

𝑆𝑢

)2

= 1

6 mm

6 mm 8 mm

8 mm 10 mm

10 mm

xxxvi

Tabel 6. Minimum Safety Factor of Shock Absorber for ASTM 9255+ASTM 40 material

Tabel.7 Minimum Safety Factor of Shock Absorber for AISI 231+ASTM 40 material

From Table. 6-7, we can see that all new shock absorber design has different safety factor values according to

all fatigue theories but all new shock absorber has safety factor more than 1. This means that all shock absorber designs

are good design safe under static loading is considered. Among new shock absorber design, the design with pitch model

and 6 mm diameter of spring made of AISI 9255 better than the others. Because this design has higher safety factor

value in all faigue theories. The displacement value of assembly AHP and femur bone are given in Table 3-4.

MODAL ANALYSIS

Modal analysis helps to determine the vibration characteristics (natural frequencies and mode shapes) of a

mechanical structure or component, showing the movement of different parts of the structure under dynamic loading

conditions, such as those due to the lateral force generated by the electrostatic actuators. The natural frequencies and

mode shapes are important parameters in the design of a structure for dynamic loading conditions. Modal analysis of

the shock absorber were performed using ANSYS software. Figure 9 shows the mode shape of the shock absorber at

its fundamental frequency and Table 8-9 shows the natural frequencies of the shock absorber design for its different

vibration modes.

A modal analysis is typically used to determine the vibration characteristics (natural frequencies and mode

shapes) of a structure or a machine component while it is being designed. It can also serve as a starting point for another,

more detailed, dynamic analysis, such as a harmonic response or full transient dynamic analysis. Modal analyses, while

being one of the most basic dynamic analysis types available in ANSYS, can also be more computationally time

consuming than a typical static analysis. In this research, point mass about 250 kg carried out using Modal Analysis

ANSYS 19.1 Workench. [12][13]

Materials Spring

Model

Diameter of


AISI 9255

&

ASTM 40

Pitch

6 2,898267 2,35471 3,583741

8 2,276542 1,849685 2,814909

10 1,77723 1,443987 2,197522

Revolution

6 2,836793 2,304829 3,507687

8 2,038059 1,655888 2,520046

10 1,70275 1,383465 2,105434



ASTM A231

&

ASTM 40

Pitch

6 2,77002 2,187856 3,42516

8 2,189452 1,729405 2,707223

10 1,709407 1,350217 2,113661

Revolution

6 2,732024 2,157911 3,378141

8 1,960354 1,548415 2,423965

10 1,639539 1,295021 2,027275

xxxvii


Table 8. Result of Modal Analysis shock absorber made of AISI 9255 (Revolution, 6 mm)


1 1 0.57145 1.2472

2 2 0.59758 1.2451

3 3 28.396 64.778

4 4 28.529 64.365

5 5 44.158 61.121

6 6 49.251 65.704

Table 9. Result of Modal Analysis shock absorber made of ASTM A231 (Revolution 6 mm)


1 1 0.57141 1.2472

2 2 0.59767 1.2451

3 3 28 63.998

4 4 28.135 63.586

5 5 43.456 60.381

6 6 48.656 64.912

xxxviii

Figure 10. Modal Analysis 9255 rev 6 mm

xxxix

Figure 11. Modal analysis ASTM A231 rev 6 mm

From the result of Modal Analysis shown in Table 8-9 and Figure 9-10, we can see that the design of shock

absorber made of ASTM A228 and AISI 9255 were safe for mode 1 and mode 2. Against as in modal analysis case, the

shock absorber made of both material has different result. This indicates that the shock absorber predicted to be safe

against mode 1-2 modal analysis but may fail under modal analysis for mode 3-6.

CONCLUSION

The object of this research was to ensure the appropriateness of shock absorber design based on finite element

analysis. In this research, six different new shock absorbers are designed. Shock absorber design have varying model

of spring and varying size of spring. The varying model and size of spring are created to reduce mass of the shock

absorber and to know the equivalent stress distribution in the shock abosrber. Static structural and modal analysis of

the shock absorber have been done using ANSYS 19.1. Based on static structural analysis results, safety factors for

fatigue life have been calculated. Fatigue calculations have been carried out for ASTM A231 and AISI 9255 materials

based on Goodman, Soderberg, and Gerber fatigue theories. FEA in this study show that all new shock absorber designs

are safe against static loading. Based on modal analysis the shock absorber design predicted to be safe under modal

analysis mode 1-2 but may fail under modal analysis mode 3-6. The best shock absorber design for under static loading

is new shock absorber design with 6 mm diameter and revolution model of spring made of AISI 9255 material because

this design is lighter than pitch model.

ACKNOWLEDGMENTS

This research was supported by internal funding from the Sepuluh Nopember Institut of Technology

REFERENCES

[1] Waleed Salman, A high-efficiency energy regenerative shock absorber using helical gears for powering low-

wattage electrical device of electric vehicles. School of Mechanical Engineering, Southwest Jiaotong

University, Chengdu, 610031, PR China. (2018)

[2] Shaun Spiteri, Application of Shock Absorber, University of Bridgeport, EJERS, European Journal of

Engineering Research and Science, Vol. 4, No. 1, January 2019.

[3] S-R Hong, Liquid spring shock absorber with controllable magnetorheological damping. Smart Structures

Laboratory, Department of Aerospace Engineering, University of Maryland, College Park, Maryland, USA

(2005)

[4] Taylor, P.H. Liquid Spring Shock Absorber Assembly US Pat. 3933344, 1976.

xl

[5] Chaitanya Kuber, Modelling Simulation and Control Of An Active Suspension System. Department of

Mechanical Engineering, Sinhgad College of Engineering, Pune, Maharashtra, India (2014)

[6] Yongjie Lu, Research on Damping Characteristic of Shock Absorber for Heavy Vehicle, Institute of

Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang, 050043, P.R. China. (2012)

[7] Ruichen Wang, Modelling, Testing and Analysis of a Regenerative Hydraulic Shock Absorber System. School

of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK. (2016)

[8] Ran Zhang, A Comprehensive Review of the Techniques on Regenerative Shock Absorber Systems, School

of Engineering, RMIT University, Bundoora Campus, East, Corner Plenty Rd and McKimmies Rd, Bundoora,

VIC 3083, Australia. (2018)

[9] Fang, Z.; Guo, X.; Xu, L.; Zhang, H. Experimental study of damping and energy regeneration characteristics

of a hydraulic electromagnetic shock absorber. Adv. Mech. Eng. 2013, 5.

[10] Manish Belwanshi, Structural Performance Improvement of Shock Absorber with Carbon Fiber and Beryllium

using ANSYS Structural, Department of Mechanical Engineering, VITS Bhopal, MP, India (2018)

[11] Xiaolin. Finite Element Modelling and Simulation with ANSYS Workbench. CRC Press, London. (2019)

[12] A. Chinnamahammad basha. Design and Analysis of Shock Absorber. M.Tech Student, Department of

Mechanical Engineering, Vigna University, India (2017)

[13] Sudarshan Martande,Y.N Jangale,N.S Motgi, “Design and Analysis of shock absorber,” IJAIEM, vol 2, no. 3,

ISSN. 2319-4847. India (2013)

[14] Ragupathi.P, Dhayanidhi. E, Arunachalam. S, Jegadeshwaran A & Kamal Hassan. P, “Design of Helical

Spring Suspension”, Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017.

[15] Suraj R. Bhosle, Shubham R. Ugle & Dr. Dhananjay R. Dolas, “Comparative Analysis of Suspension System

Coil Spring Using FEA”, Imperial Journal of Interdisciplinary Research (IJIR), Vol-3, Issue-1, 2017

[16] Manga Hymanjali, Design and Analysis of Shock Absorber, Departemnt of Mechanical Engineering,

Warangal Institute of Technology and Science, Warngal, India, Volume 3, Issue 8, August – 2018

[17] Tongyi Xu, Ottawa, Canada, “DESIGN AND ANALYSIS OF A SHOCK ABSORBER WITH A VARIABLE

MOMENT OF INERTIA FLYWHEEL FOR PASSIVE VEHICLE SUSPENSION” A thesis submitted to the

Faculty of Graduate and Postdoctoral Studies in Applied Science in Mechanical Engineering, 2013.

xli

Lampiran 8. Draft untuk Jurnal Materials & Design

Finite Element Modelling and Analysis of a Novel Shock Absorber

Design

Yuli Setiyorini1, Sungging Pintowantoro1, Fahny Ardian1, and Anni Rahmat2

1) Materials and Metallurgical Engineering Department, Faculty of Industrial Technology

and System Engineering, Institut Teknologi Sepuluh Nopember (ITS). Jl. Arief Rahman

Hakim, Surabaya, 60111, Indonesia

2) Chemical Engineering Department, Semen Indonesia International University, Gresik,

61122, Indonesia

*Corresponding author e-mail: [email protected]

Abstract: The shock absorber is a component designed to smooth out the shock impulse and

dissipate kinetic energy. The engine is the main power of the vehicle and the most direct reason that

cause the vibration of the vehicle. If the shock absorber cannot control the vibration, will make other

parts of the body has seriously affect like vehicle handling stability and shorten the vehicle's

component life. The shock absorber system connects a vehicle to its wheels and contributes to the

vehicle’s road handling and braking for better safety and driving pleasure and offering a comfortable

ride well isolated from road noise, bumps, vibrations. In this paper, the authors propose a new shock

absorber design that it can smooth out or damp shock impulse, dissipate kinetic energy, and reduced

amplitude of disturbances with light weight. When a vehicle is through on a level road and the

wheels strike a bump, the spring is compressed. The compressed spring will attempt to return to its

normal loaded length and will rebound past its normal height, causing the passenger and body

vehicle to be lifted. The rebound process is repeated over and over, a little less each time, until the


xlii

up-and-down movement finally stops. The design of spring in the shock absorber system is a vital

component. In this research, a shock absorber is created using SolidWorks 2014. The model is also

varying diameter and revolution number of the spring. Structural analysis and modal analysis are

done on the shock absorber by varying material for ASTM A231 and ASTM A228 using ANSYS

19.1. The analysis is done by considering loads, bike weight with 2 person passengers. Structural

analysis was done to validate the strength of the materials and design. Modal analysis was done to

know the displacements for different frequencies for the number of modes. Comparison is done for

two materials with a varying diameter and revolution number of springs to verify the best materials

and design for the shock absorber. Based on the structural analysis result, the safety factor for the

fatigue life of the shock absorber design has been calculated based on Goodman, Soderberg, and

Gerber fatigue theories. The stresses and strains were also found to be optimum which leads to

increase of structural strength of the shock absorber.

Keywords: Finite Element Analysis, Shock Absorber, Structural Analysis, Materials, Design

1. Introduction

The shock absorber system has used widely in different fields, such as civil, aerospace and

automotive engineering, for vibration absorption and system stability [1][2]. The shock absorber is

a mechanical component of vehicle that function to reduce the vibrations. The shock absorber

includes spring, valves and orifices used to manage the flow of oil and gasses through an internal

piston [3]. The shock absorbers minimize the effect of traveling over rough ground, leading to

improved ride quality and vehicle handling. The shock absorbers in motorcycle use valving of oil

or gas to absorb excess energy from the springs cause by traveling. Spring was chosen by the factory

based on the weight of the vehicle (loaded and unloaded). During hysteresis in the tire, they damp

the energy stored in the motion of the unsprung weight up and down [4]. Effective of wheel

motorcycle bounce damping may require tuning shocks to an optimal resistance [5][6]. Spring of

the shock absorbers in motorcycle commonly use coil springs. Motorcycle usually employ both

xliii

hydraulic shock absorbers and springs. In this combination, shock absorber refers specifically to the

hydraulic piston that absorbs and dissipates vibration and energy [7][8].

Hydraulic and pneumatic shock absorbers usually take the form of a cylinder with a sliding

piston inside. The cylinder is filled with a fluid or gas. This fluid-filled piston/cylinder combination

is a dashpot. One of design decision, when designing or choosing the shock absorber, is where that

energy will release. In most shock absorber, the excess energy is converted to heat inside the viscous

fluid. In hydraulic cylinders, the hydraulic fluid will heat up, while in gas cylinders, the hot gasses

will exhaust to the atmosphere or environment. In general, the shock absorbers help cushion vehicle

on uneven tracks [9].

The spring of shock absorber able to operate in any conditions under a wide range of

temperatures. The spring store energy rather than dissipating it. Metal spring type shock absorbers

are used then measures should be provided to limit oscillations. Metal springs are often used with

viscous dampers. There are a number of different types of metal springs including helical springs,

bevel washers(cone-springs), leaf springs, ring springs and etc. Each spring type has its own

operating characteristics [10].

Finite Element Analysis (FEA) is a computer-based numerical methode to calculate the

phenomena and behavior of engineering structures. It can be used to determine stress, strain,

deformation, safety factor, vibration, buckling behavior and other phenomena. It can be used to

calculate either small or large-scale deformation under loading or unloading. It can analyze elastic

deformation or plastic deformation. This technique is also distinguished from finite differential

equations, for which although the steps into which space is divided are finite in size, there is little

freedom in the shapes that the discreet steps can take. FEA is a way to deal with structures that are

more complex than can be dealt with analytically using partial differential equations. FEA deals

with complex boundaries better than finite difference equations and gives answers to structural

problems.

xliv

In FEA, the actual continuum or body of matter like solid, liquid or gas is represented as an

assemblage of subdivisions called finite elements. These elements considered to be interconnected

at specified joints called nodes or Nodal points. The nodes usually lie on the element boundaries

where adjacent elements considered to be connected since actual variation of the field variable

inside a finite variable inside a finite element can be approximated by a function. These approximate

functions are defined in terms of the value of the field’s variables at the nodes. A static structural

analysis determines the stresses, strains, and deformation in structures or components caused by

loads that do not induce significant inertia and damping effects. Steady loading and transient loading

response conditions are assumed; that is, the loads and the structure's response and phenomena are

assumed to vary slowly with respect to time [1][2][5][11].

The research about shock absorber simulation has been done, A. Chinnamahammad bhasha,

N. Vijay rami reddy, B. Rajnaveen, worked on suspension system also created and a 3D model is

generated using CATIA V5 R21. The project used spring steel, phosphor bronze, berilium copper

and titanium alloy as spring material. They considered weight of bike with double riding. Final

comparison is done for different materials to calculated best material for spring in the shock

absorber. Modeling is done in CATIA and analysis is done in ANSYS [12]. Syambabu Nutalapati,

in the research a shock absorber design and a 3D model was created using CATIA. Static structural

and modal analysis are done on the shock absorber by varying material for Spring Steel and

Molybdenum [13]. Pinjarla Poornamohan, Lakshmana Kishore, In their project a shock absorber is

designed and a 3D model is created using Pro/Engineer. The size of spring is varied and the material

is spring steel and beryllium copper. Structural analysis is done to verify the displacement at number

of nodes at different frequencies using Ansys [14]. Rahul Tekade, Chinmay Patil, has carried

Structural and Modal Analysis of Shock Absorber of Vehicle to sustain more vibrations at all

conditions [15].

xlv

Sudarshan et al. has created a new methodology which allows designing the partr of a shock

absorber by using finite element analysis (FEA). In production of shock absorbers, it is difficult to

know the accuracy and precision of shock absorber which doesn’t fail. The shock absorber is

generated by using CAD software and analysed in ANSYS workbench by considering the weight

of vehicle. In the results, deflection and stress induced in the shock absorber are studied [16].

2. CAD and Finite Element Model

2.1 CAD Model

Shape and size of the shock absorber component have significant influence on the

performance of shock absorber a during travelling period especially spring. The important

component of a shock absorber are upper mount, piston rod, cylinder and lower mount [17]. All the

different compnent of the shock absorber are created separately in SolidWorks 2014 software and

all the individual parts of the shock absorber are assembled in the SolidWorks 2014 shown in Fig.

1-4. The design of shcok absorber must appropriate to the vehicle. In this research a series of shock

absorber design with different diameter and revolution number of springs shown in Table 1. Spring

with different diameter and revolution number generally have different stress concentration and

stress distribution and perhaps to increase lifetime and safety factor of the shock absorber. Spring

with large diameter provide maximal stress distribution. However, it increased the weight of shock

absorber and increase the energy consumption of vehicle. In other hand, spring with minimum

diameter will decrease the weight of shock absorber and increase the possibility of failure caused

by stress concentration and poor stress distribution [18]. Therefore, this research needs to be done

in order to obtain an optimal shock absorber design in terms of weight, comfort during tarveling

and good mechanical properties. In this research, 6 different shock absorber design with varying

diameter and revolution number of spring are generated to achieve best shock absorber design.

The model of shock absorber was imported in ANSYS 19.1 and meshing is done for analysis

shown in Fig. 5. Structural analysis and modal analysis performed applying average two passengers

xlvi

and stress distribution, total deformation and safety factor was calculated. Maximal and minimal

stress (von misses) variation with respect to time was recorded. Maximal and minimal stress

variation were used to determine safety factor and properness of the shock absorber. On the lower

mount of the shock absorber, a fixed support is assigned to withstand the forces acting on the shock

absorber as shown in Fig. 6. Whenever a certain external load is applied on the upper mount of a

shock absorber, the shock absorber cylinder moves down and compresses the spring. For applying

the load on the shock absorber, the weight of the vehicle with two passengers is calculated

[11][12][13][14].

In this project a new design of shock absorber has been simulated to consider safety factor

to estimate the properness of the shock absorber. The purpose of a novel design for a shock absorber

was obtained light, reliable, good and durable design [19]. The purpose of making this new design

is to produce a shock absorber design with the ability to have the maximum capability with the

lightest weight. The shock absorber design has to reduce the stress distribution during loading and

unloading, perhaps will increase the lifetime and properness of the shock absorber [20]. With the

variety of spring diameter and revolution number in the shock absorber is expected to reduce the

weight and distribute the stress of the shock absorber [21][22].

2.2 Finite Element Model

In the present research an attempt has been made to consider safety factor and stress

distribution to determine the useful life of the shock absorber. First a finite element model of the

shock absorber was created in SolidWorks 2014. The developed model was imported in ANYS 19.1

using parasolid extension. Static structural and modal analysis of shock absorber carried out to

evaluated about the safety factor and appropriatennes of the shock absorber model. Static analysis

was performed applying average weight of vehicle and two passanger (7500 N). A CAD model of

shock absorber was created in SolidWorks 2014 as per dimension in Fig. 1-4 and saved in Parasolid

format, which was then imprted in ANSYS 19.1 for further simulation. The shock absorber was

xlvii

defined with linear elastic isotropic material. Table 2 shown ASTM A231 and ASTM A228

properties were assigned to the spring of shock absorber and ASTM 40 were given to the upper and

bottom component. Standard surface contact was defined between bottom and upper component.

Coefficient of friction equal to 0.1 was assumed as the component is generally well lubricated by

fluid or oil. The simulation of the shock absorber which must be taken into account not to cause

failure of the shock absorber .To evaluated how structural and modal analysis result differ from

each other design of shock absorber, with varying the materials, model and diameter of the spring.

Finite element analysis of the shock absorber was carried out using ANSYS 19.1 on a P4 2.0 GHz

Intel processor PC. Static structural and modal analysis of shock absorber have to conducted to

ensure about the safety factor and properness of the shock absorber design [21][22][23].

3. Results and Discussion

FEA of the shock absorber are carried out using ANSYS 19.1. The rules of optimization in

this research are to ensure that the shock absorber design is proper or not. The maximum equivalent

stress on the shock absorber should be lower than the endurance limit of the materials. In addition,

the stress on the shock absorber design should be evenly distributed. The von Mises stress was

adopted as the criterion in this work. The von Mises yield criterion is part of a plasticity theory that

applies best to ductile materials, such as metals. Prior to yield, the material response is assumed to

be elastic. In materials science and engineering the von Mises yield criterion can be formulated in

terms of the von Mises stress. The von Mises stress is used to predict yielding of materials under

any loading condition from results of simple uniaxial tensile tests. The von Mises stress has

therefore also been widely used in the finite element analysis of artificial joints. Table 3 shows the

von Mises stress and total deformation on the shock absorber design under static loading. Fig. 7-8

show the von Mises stress on the shock absorber design under static loading. The result presented

in this study indicated that when a shock absorber is loaded. From the result can concluded that in

shock absorber design made of ASTM A231 and ASTM A288 is safe because the maximum von

xlviii

misses stress in below the yield point of materials. The same result was obtained from dyanmics

(transient structural) analysis shown in Tabel 4 and Fig. 9-10. From the result can concluded that in

shock absorber design made of ASTM A231 and ASTM A288 is safe under dynamic loading

because the maximum von misses stress in below the yield point of materials [24].

In other hand the shock absorber design made of ASTM A228 with diameter 9 mm and

revolution number 9 is the best design for under static loading. However, for under dynamic loading

the shock absorber design made of ASTM A231 with diameter of spring 8.5 mm and revolution

number 14 is the best design.

Goodman, Soderberg and Gerber theories was used for determining of safety factor of shock

absorber designs. In this research, safety factor of the shock absorber is evaluated using ANSYS

Workbench. Safety factor calculations of the shock absorber are conducted for ASTM A231 and

ASTM A228 materials. In the FEA, the materials are considered to be isotropic elasticity. Therefore,

the safety factor was ensured to be more than 1 that conclude the shock absorber design is safe [25].

The formulation of goodman, soderberg and gerber theories can be seen in Table 5.


2 (1)


2 (2)

N = Safety Factor

Se = Endurance Limit (MPa)

Su = Ultimate Tensile Strength (MPa)

𝝈𝒎 = Mean Stress (MPa)

𝝈𝒂 = Alternating Stress (MPa)

From Table. 6-7, we can see that all new shock absorber design has different safety factor

values according to all fatigue theory, but all new shock absorber has safety factor more than 1. This

means that all shock absorber designs are good design safe under static and dynamic loading is

xlix

considered. Among new shock absorber design, the design with diameter 8.5 mm and revolution

number 14 made of ASTM A231 better than the others. Because this design has higher safety factor

value in all fatigue theories.

4. Modal Analysis

Modal analysis helps to determine the vibration characteristics (natural frequencies and

mode shapes) of a mechanical structure or component, showing the movement of different parts of

the structure under dynamic loading conditions, such as those due to the lateral force generated by

the electrostatic actuators. The natural frequencies and mode shapes are important parameters in the

design of a structure for dynamic loading conditions. Modal analysis of the shock absorber was

performed using ANSYS software. Fig. 11 shows the mode shape of the shock absorber at its

fundamental frequency and Table 8-11 shows the natural frequencies of the shock absorber design

for its different vibration modes [16].

A modal analysis is typically used to determine the vibration characteristics (natural

frequencies and mode shapes) of a structure or a machine component while it is being designed. It

can also serve as a starting point for another, more detailed, dynamic analysis, such as a harmonic

response or full transient dynamic analysis. Modal analyses, while being one of the most basic

dynamic analysis types available in ANSYS, can also be more computationally time consuming

than a typical static analysis. In this research, point mass about 250 kg carried out using Modal

Analysis ANSYS 19.1 Workbench. [12][13]

From the result of Modal Analysis shown in Table 8-11 and Fig. 12-15, we can see that the

design of shock absorber made of ASTM A228 and ASTM A231 were safe for mode 1 and mode

2. Against as in modal analysis case, the shock absorber made of both material has different result.

This indicates that the shock absorber predicted to be safe against mode 1-2 modal analysis but may

fail under modal analysis for mode 3-6.

l

5. Conclusion

The object of this research was to ensure the ability and properness of shock absorber design

based on finite element analysis. In this research, six different new shock absorbers are designed.

Shock absorber design have varying diameter and revolution number of spring. The varying

diameter and revolution number of springs are created to reduce mass of the shock absorber and to

know the equivalent stress distribution in the shock abosrber. Structural and modal analysis of the

shock absorber have been done using ANSYS 19.1. Based on structural analysis results, safety

factors for fatigue life have been calculated. Fatigue calculations have been carried out for ASTM

A228 and ASTM A231 materials based on Goodman, Soderberg, and Gerber fatigue theories. FEA

in this study show that all new shock absorber designs are safe against static and dynamic loading.

Based on modal analysis the shock absorber design predicted to be safe under modal analysis mode

1-2 but may fail under modal analysis mode 3-6. The best shock absorber design for under static

and dynamic loading is new shock absorber design with 9 mm diameter and 12 revolution number

of spring made of ASTM A231 material because this design is lighter than other design.

Acknowledgments

This research was supported by internal funding from the Sepuluh Nopember Institut of

Technology

References

[18] Waleed Salman, A high-efficiency energy regenerative shock absorber using helical gears

for powering low-wattage electrical device of electric vehicles. School of Mechanical

Engineering, Southwest Jiaotong University, Chengdu, 610031, PR China. (2018)

[19] Shaun Spiteri, Application of Shock Absorber, University of Bridgeport, EJERS, European

Journal of Engineering Research and Science, Vol. 4, No. 1, January 2019.

[20] S-R Hong, Liquid spring shock absorber with controllable magnetorheological damping.

Smart Structures Laboratory, Department of Aerospace Engineering, University of

Maryland, College Park, Maryland, USA (2005)

[21] Taylor, P.H. Liquid Spring Shock Absorber Assembly US Pat. 3933344, 1976.

[22] Chaitanya Kuber, Modelling Simulation and Control of An Active Suspension System.

Department of Mechanical Engineering, Sinhgad College of Engineering, Pune,

Maharashtra, India (2014)

li

[23] Yongjie Lu, Research on Damping Characteristic of Shock Absorber for Heavy Vehicle,

Institute of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang,

050043, P.R. China. (2012)

[24] Ruichen Wang, Modelling, Testing and Analysis of a Regenerative Hydraulic Shock

Absorber System. School of Computing and Engineering, University of Huddersfield,

Queensgate, Huddersfield HD1 3DH, UK. (2016)

[25] Ran Zhang, A Comprehensive Review of the Techniques on Regenerative Shock Absorber

Systems, School of Engineering, RMIT University, Bundoora Campus, East, Corner Plenty

Rd and McKimmies Rd, Bundoora, VIC 3083, Australia. (2018)

[26] Fang, Z.; Guo, X.; Xu, L.; Zhang, H. Experimental study of damping and energy

regeneration characteristics of a hydraulic electromagnetic shock absorber. Adv. Mech. Eng.

2013, 5.

[27] Manish Belwanshi, Structural Performance Improvement of Shock Absorber with Carbon

Fiber and Beryllium using ANSYS Structural, Department of Mechanical Engineering,

VITS Bhopal, MP, India (2018)

[28] Xiaolin. Finite Element Modelling and Simulation with ANSYS Workbench. CRC Press,

London. (2019)

[29] A. Chinnamahammad basha. Design and Analysis of Shock Absorber. M.Tech Student,

Department of Mechanical Engineering, Vigna University, India (2017)

[30] Nutalapati Syambabu. Structural Analysis of Shock Absorber by Using Ansys. Department

of Mechanical Engineering Sasi Institute of Technology & Engineering, Taddepalligudem,

Andhara Pradesh, India. (2015)

[31] Pinjarla Poornamohan, and T. Lakshmana Kishore, “Design and analysis of shock

absorber,” International Journal of Research in Engineering and Technology, vol. 1, Issue

4, pp. 578–592, December 2012

[32] Rahul Tekade1, Chinmay Patil, “Structural and Modal Analysis of Shock Absorber of

Vehicle”, InternationalJournal of Engineering Trends and Technology (IJETT) – Volume

21 Number 4 – March 2015, ISSN: 2231-5381, Page 173-186.

[33] Sudarshan Martande,Y.N Jangale,N.S Motgi, “Design and Analysis of shock absorber,”

IJAIEM, vol 2, no. 3, ISSN. 2319-4847. India (2013)

[34] Ragupathi.P, Dhayanidhi. E, Arunachalam. S, Jegadeshwaran A & Kamal Hassan. P,

“Design of Helical Spring Suspension”, Imperial Journal of Interdisciplinary Research

(IJIR) Vol-3, Issue-4, 2017.

[35] Suraj R. Bhosle, Shubham R. Ugle & Dr. Dhananjay R. Dolas, “Comparative Analysis of

Suspension System Coil Spring Using FEA”, Imperial Journal of Interdisciplinary Research

(IJIR), Vol-3, Issue-1, 2017

[36] Manga Hymanjali, Design and Analysis of Shock Absorber, Departemnt of Mechanical

Engineering, Warangal Institute of Technology and Science, Warngal, India, Volume 3,

Issue 8, August – 2018

[37] Tongyi Xu, Ottawa, Canada, “Design and Analysis Of A Shock Absorber With A Variable

Moment Of Inertia Flywheel For Passive Vehicle Suspension” A thesis submitted to the

Faculty of Graduate and Postdoctoral Studies in Applied Science in Mechanical

Engineering, 2013.

[38] Nutalapati Syambabu. Structural Analysis of Shock Absorber by Using Ansys. Department

of Mechanical Engineering Sasi Institute of Technology & Engineering, Taddepalligudem,

Andhara Pradesh, India. (2015)

lii

[39] C. Dixon, John. The Shock Absorber Handbook Second Edition Wiley-PEPublising Serius,

UK (2007)

[40] W. Shivaraj Sighn, N. Srilatha. Design and Analysis of Shock Absorber: A Review. Mtech

Student, VNR VJIET, Bachupalty, Hyperbad 500090, India

[41] ANSYS. ANSYS Theory Reference Manual, Release 8.0 ANSYS Inc.; 2003

[42] Teoh SH. Fatigue of biomaterials: a review. Int J Fatigue 2000;22:825-37.

Figure 1. Shock Absorber

liii

Figure 2. Top Component

liv

Figure 3. Spring (a) Revolution Number 12, (b) Revolution Number 13, (c) Revolution Number

14

lv

Figure 4. Bottom Component

lvi

Figure 5. Meshing in ANSYS

lvii

Figure 6. Applied Force

lviii

Figure 7. Stress Distribution on the shock absorber under static loading for ASTM A228

lix


lx

Figure 9. Stress Distribution on the shock absorber under dyanmic loading for ASTM A228

lxi


lxii

\


lxiii

Figure 12. Modal analysis of shock absorber (8.5 mm Revolution Number 14) for ASTM A228

lxiv


lxv

Figure 14. Modal analysis of shock absorber (9 mm Revolution Number 12) for ASTM A228

lxvi


lxvii

Table 1. Variabel Research

Materials Diameter of Spring Revolution Number

ASTM A228

8.5

12

13

14

9

12

13

14

ASTM A231

8.5

12

13

14

9

12

13

14

Table 2. Materials Properties

Materials Young

Modulus

(GPa)

Possion

Ratio

Yield

Strength

(MPa)

UTS (MPa) Density

(gr/cm3)

ASTM 40 180 0.29 200 310 7.5

ASTM A228 200 0.29 350 650 7.8

ASTM A231 190 0.29 1570 1790 7.8

Table 3. Stress Distribution of Shock Absorber Under Static Loading

Materials Diameter of

Spring

Revolution

Number

Max. Von

Misses

Stress

(MPa)

Min. Von

Misses

Stress

(MPa)

Total

Deformation

(mm)

ASTM

A228

8.5

12 220.86 0.00072504 5.3512

13 201.91 0.00069552 5.3048

14 202.08 0.00067653 5.31

9

12 200.91 0.00070944 5.2765

13 201.18 0.00073556 5.281

14 201.42 0.0010543 5.2845

ASTM

A231

8.5

12 221.01 0.00072524 5.3558

13 202.05 0.00069135 5.3091

14 202.21 0.00067712 5.3139

9

12 201.1 0.00070329 5.2821

13 201.35 0.00072915 5.2863

14 201.58 0.0010512 5.2896

lxviii

Table 4. Stress Distribution of Shock Absorber Under Dynamic Loading

Tabel 5 Fatigue Theories


Goodman (

𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑢

) =1

𝑁

Soderberg (

𝜎𝑎

𝑆𝑒

) + (𝜎𝑚

𝑆𝑦

) =1

𝑁

Gerber (

𝑁. 𝜎𝑎

𝑆𝑒

) + (𝑁. 𝜎𝑚

𝑆𝑢

)2

= 1


Spring

Revolution

Number

Max. Von

Misses Stress

(MPa)

Min. Von

Misses

Stress

(MPa)

Total

Deformation

(mm)

ASTM

A228

8.5

12 294.16 0.02534 19.904

13 247.48 0.01466 19.853

14 221.56 0.032757 19.939

9

12 270.64 0.014585 19.601

13 250.73 0.010557 19.58

14 265.74 0.014564 19.652

ASTM

A231

8.5

12 247.73 0.025916 20.194

13 235.7 0.0094194 19.905

14 211.21 0.032553 20.006

9

12 257.65 0.014006 19.647

13 239.71 0.0045054 19.707

14 253.11 0.014261 19.698

lxix

Tabel 6. Minimum Safety Factor of Shock Absorber under static Loading


Spring

Revolution

Number

Goodman Soderberg Gerber

ASTM A228

8.5

12 1,826717 1,442892 2,258705

13 1,998162 1,578313 2,470693

14 1,996481 1,576985 2,468615

9

12 2,008107 1,586169 2,482991

13 2,005412 1,58404 2,479658

14 2,003024 1,582153 2,476706

ASTM A231

8.5

12 5,027084 4,817577 6,215905

13 5,498817 5,26965 6,799194

14 5,494466 5,26548 6,793814

9

12 5,524793 5,294544 6,831314

13 5,517934 5,287971 6,822832

14 5,511641 5,28194 6,815053

Tabel 7. Minimum Safety Factor of Shock Absorber under dynamic Loading


Spring

Revolution

Number

Goodman Soderberg Gerber

ASTM A228

8.5

12 1,369523 1,081736 1,693407

13 1,630262 1,287695 2,015804

14 1,821046 1,438352 2,251727

9

12 1,49075 1,1775 1,843297

13 1,60912 1,271002 1,989658

14 1,518238 1,199212 1,877286

ASTM A231

8.5

12 4,485038 4,298097 5,545735

13 4,713837 4,517375 5,828603

14 5,260638 5,041354 6,504796

9

12 4,312274 4,132545 5,332083

13 4,634944 4,441776 5,731039

14 4,389626 4,206673 5,427729

Tabel 8. Modal Analysis for ASTM A228 (8.5 mm, Rev 14)

No Mode Frequency (Hz) Total Deformation (mm)

1 1 0,50155 1,0588

2 2 0,52454 1,0664

3 3 42,825 46,499

4 4 43,272 45,98

5 5 68,191 44,571

6 6 73,486 48,433

lxx

Tabel 9. Modal Analysis for ASTM A231 (8.5 mm, Rev 14)


1 1 0,50039 1,0589

2 2 0,52314 1,0664

3 3 41,593 46,316

4 4 42,02 45,796

5 5 66,116 44,398

6 6 71,395 48,271

Tabel 10. Modal Analysis for ASTM A228 (9 mm, Rev 12)


1 1 0,69734 1,5002

2 2 0,72959 1,4969

3 3 52,534 47,553

4 4 53,238 46,984

5 5 78,452 10,791

6 6 84,291 45,271

Tabel 11. Modal Analysis for ASTM A231 (9 mm, Rev 12)


1 1 0,69545 1,5002

2 2 0,72741 1,4969

3 3 51,027 47,36

4 4 51,697 46,785

5 5 78,236 17,315

6 6 81,94 42,898

LAPORAN AKHIR PENELITIAN PROTOTIPE DANA ITS 2020

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