Investigation on the effect of shear connector in composite space structures

466 Journal of Structural EtnginEEring Vol. 40, no. 5, dEcEmbEr 2013 - January 2014

Journal of Structural EngineeringVol. 40, no. 5, december 2013 - January 2014 pp. 466-476 No. 40-48

Investigation on the effect of shear connector in composite space structuresK.n. lakshmikandhan*, P. Sivakumar*, r. ravichandran*,, S. arul Jayachandran and r. Senthil***

Email: [email protected]

*cSir-Structural Engineering research centre, cSir campus, taramani, chennai - 600 113, tamil nadu, india.**department of civil Engineering, indian institute of technology, madras, chennai - 600 25, tamil nadu, india.

***department of civil Engineering, anna university, chennai - 600 25, tamil nadu, india.

received: 08 June 2012; accepted: 26 June 2012

Keywords: Space frame; double layer; steel concrete composite; shear connector; fEm.

Space frame structures are efficient solution to cover large area with minimum material and cost. Space frame structures are formed with number of truss members connected together by means of nodes, which are specially made to transfer load from individual member to the whole system. these structures are built up from simple prefabricated units of standard size and shape in the factory and assure quality and time saving. the mass production of prefabricated units can easily be handled, transported and assembled. Space structures allow great flexibility in deciding different layout and positioning of columns. the last three decades saw the emergence of a new generation of space structures developed considering the parameters to address the usual high cost problem of this type of structure. the economy and performance of the space structures depends on

many parameters including topology, span, support conditions, external loading (heavy, moderate, light), span to depth ratio, support locations etc. the degree of indeterminacy of space structures generally have about 25 percent of its total number of members which is most considered factor for the uncertainties1. the space structures are more sensitive to the imperfection, which introduces the initial forces and these forces in the members are distributed uniformly and effectively. the failure of one or few critical compression members of Space structures leads to adjacent member failure and frequently reported the catastrophic failure total structure. a number of research works have been carried out to improve the performance of the individual chord members and the overall space structure behavior, using numerical, analytical and experimental means.

space structures are common in covering large area with few or no intermittent supports. The catastrophic failures of space structures are frequently reported and it urges to develop suitable techniques to prevent such failures. The composite space structures are found to be an efficient solution, in which the forces in the critical compression members are redistributed and safe guarded with concrete slabs. In this study, numerical studies were conducted using a standard finite element analysis package. Effect of shear connectors with varying heights on the behaviour of the space structure is studied. results are compared with the steel space structure and composite space structure with full shear interaction. The maximum deflection observed in the steel space structure for the service load is less than span/300 and the maximum deflection observed in the steel concrete composite space structure for the service load is less than span/360, which ensures the serviceability conditions. The results show about 20 to 30 percent of reduction in deflection with about 250 percent increase in stiffness due to the composite action for the service load. The results substantiate that the length of shear connector should be equal to the concrete depth for more efficient composite interaction. The composite action is more effective and efficient in composite space structure for larger spans compared to shorter spans.

Journal of Structural EnginEEring 467 Vol. 40, no. 5, dEcEmbEr 2013 - January 2014

investigations also carried out to develop methods to overcome the failure of individual critical chord members and the overall truss behavior. Preventing the overloading, by introducing heavier of sections, by removing some members, by installing force control devices and providing top concrete slabs are the few successful methods were developed to improve the behaviour of space structure.

the sudden collapse of the large Hartford coliseum space roof, connecticut, uSa in 1978 under half its design load become a question on redundancy of these structures2. failure of one or few members can trigger other member to fail rapidly. the high degree of indeterminacy plays no part in controlling the progressive failure and causes adverse effect by introducing the residual stresses due to any uncertainties in the form of initial geometric imperfections, member end eccentricities, joint flexibility, imperfect boundary conditions and the human error. Hanaor et al1 presented the collective information on the various methods practiced to modify the behaviour of the double layer grids. the behaviour of space truss structure, particularly, the double layer truss system under service loads is generally within elastic range and can be easily determined3. Space structure behaviour under extreme load condition and beyond the elastic range can obtained through both numerical and experimental investigation.

many researchers2,4-8 carried out experiments to study the ultimate behaviour of the space structures and reported that the buckling individual compression members caused the catastrophic progressive failure of space structure. also, it is observed that the buckling load of the failed member in the truss matches the individual member test under compression. Several works were carried out to overcome the brittle behaviour by improving the ductility and the overall truss behaviour of space structure2,14-15. Schmidt et.al2, Smith16 and El-Sheikh15 demonstrated the effect of under designed bottom chord compression members, over designed top chord compression member and eccentric diagonals. all these techniques improved the load carrying capacity of truss and not the brittle nature of failures. agerskov8 came with a solution by choosing relatively long tension members and relatively short compression member for the optimum solution. murtha-Smith13 found that the space truss

can be protected from the progressive failure by over designing the compression members at the diagonals along and adjacent to the column line and particularly at middle half of the span.

during the same era, the composite system was developed and achieved cost reduction, improvement in the ductility and stability. El-Sheikh and El-bakry17 presented an overall view on the work carried out on the effect of composite action on space truss. four different techniques are discussed to develop composite action efficiently. In all the four methods, the use of corrugated decking sheets and welded shear studs were used. El-Sheikh and mcconnel18, El-sheikh15,19,20 studied the space truss behaviour with concrete composite slab at top chord and reported the efficiency in altering the ductile behaviour. also, they reported that the composite space truss is uneconomical for small spans. El-Sheikh21 tried to improve the buckling compression member behavior with lack of fit in different top, middle, bottom and diagonal members and eccentric joints in an attempt to identify the most critical areas in which no imperfect members should be used. lakshmikandhan et al.22,23 presented the effect of different angle of inclination of diagonal members in varying range of spans. in this study, the authors examined the behavior of trusses with a constant depth and constant grid size. they reported that the trusses perform well when the angle of inclination of diagonal members is between 40 and 60 degree and they suggested that an angle of inclination of 45 degree and 60 mm concrete slab thickness is efficient. Lakshmikandhan et al.24 presented a parametric study on space structure with different spans and reported the efficiency of composite space structure over the steel space structure. from the review on the earlier investigations, the sudden progressive failure due to compression member buckling is frequently reported and several methods have been adopted to overcome this brittle failure. in these methods, it is frequently reported as the provision of composite slab on the top of the space grid effectively enhances the compression capacity of top chord members. the steel space structure and concrete slab are interconnected through shear connector, so that the composite action is ensured.

in the earlier studies, shear connector’s geometry and material were not considered in fE models. the nodes between the concrete and steel truss are kept


common by assuming the full shear interaction and the resultant forces are directly solved. the interaction between the steel truss and concrete slab depends on the type, size and properties of shear connector used which emphasizes to investigate the composite space structure with the shear connector. the present study is intended to arrive at an efficient length of shear connector to obtain an efficient composite action between the space truss and the concrete slab. The above deficiency in modeling of composite space truss is included in the present study. The finite element modeling is carried out for 10 m and 20 m span steel concrete composite space structure including modeling of shear connector. the results are compared with non-composite space frame and composite space frame with full shear interaction. The study is extended with experimental work and compared with the analytical results.

FINITe eLeMeNT ModeLING

the development in the computer and the computer software simplified the behavioral prediction of the structures. the selection of a mathematical model to simulate the response of a structure is a very important step in any analysis. the fEm involves dividing a structure into a discrete number of elements from which an approximate numerical solution is obtained. With the ease of programming the fEm on personal computers, this approach provides an accurate solution for many structural analysis problems. the accuracy of the results depends on the selection of the suitable elements with the appropriate material characteristic modeling. The finite element analysis and design of the non-composite space structure and the composite space structure are carried out in conjunction with the standard design module. While modeling the composite space structure in Stadd Pro, the edge nodes of the concrete slab element are directly connected with the adjacent space structure nodes rigidly. the material property for the truss members are assigned with the properties of mild steel and the concrete slab is assigned with m25 concrete elastic and nonlinear properties.

the steel space structure is initially analyzed in Stadd Pro as the initial preparation for obtaining the optimum steel section. the weight optimization technique is adopted to obtain the suitable sections. the optimization procedure starts with an assigned member from the data base which is an existing steel

table or the “user defined” steel table. The selection of the steel section for the entire structure was taken from the optimization through successive analysis and design iterations. the optimization is based on member stiffness contributions and corresponding force distributions. the optimum member size is determined based on a successive iteration technique from the listed group steel specifications. The sizes of the members are assigned based on their individual force values for obtaining the optimum weight of the structure. the linear elastic properties were used in the analysis. the modulus of elasticity of 2.1*105 n/mm2 and Poisson’s ratio of 0.3 were used for the steel sections and the modulus elasticity of 2.5*105 n/mm2 and Poisson’s ratio 0.18 are used for the concrete in the Stadd Pro analysis.

the member sizes obtained from the weight optimization are practically difficult to implement due to numerous sections. the use of numbers of sections escalates the cost for fabrication, workmanship and installation which needs to restrict the number of sizes by grouping. grouping of the members from the optimized sections is carried out for an economical solution. it is considered to use 2-3 members in top, inclined and bottom layers, such that the whole structure should be developed with a maximum of 6-9 different sections. the grouping and regrouping of the members is continued to obtain a suitable section to satisfy various code provisions. these optimum sections are used for the further study in anSyS. in the finite element model, both the linear and nonlinear material properties are used.

Modeling of space structure in ANsys

ANSYS is a general and multi purpose finite element analysis software with extensive element library. This element library is used to model the non-composite space structure and the composite space structure with the appropriate elements. the isometric view of the non-composite space structure (which is designated as NCT) and the composite space structure (designated as CT) are shown in Fig. 1.

the space structure members are modeled with two nodded PIPE16 elements with six degrees of freedom. PiPE16 element in anSyS is used to represent the top, bottom and diagonal chord members of the space structure. It is a uniaxial element with tension-compression, torsion, and bending capabilities. The element has six degrees of


freedom at two nodes with translation in the nodal x, y, and z directions and rotation about the nodal x, y, and z axes. The geometry, node locations, and the pipe outer diameter and wall thickness are used to represent the pipe section. the concrete slab is modeled with eight noded Solid65 elements, which are having cracking and crushing capabilities. Solid65 is more appropriate element used for the 3-d modeling of solids with or without reinforcing bars (rebar). The element is defined by eight nodes having three degrees of freedom at each node: The SOLID65 is capable of cracking (in three orthogonal directions), crushing, plastic deformation, and creep. the rebar are capable of tension, compression and also capable to trace plastic deformation and creep. the shear connectors are modeled with linK8 elements which inter connects the steel space structure and concrete slab elements as shown at section x-x in Fig. 2.

TM

Concrete slab

IM

IM

X X

BM

BM

BM = Bottom Chord Member

BM = Bottom Chord Member

IM = Inclined Member

IM = Inclined Member

TM = Top Chord Member

fig. 1 typical isometric view of nct and ct structures

CS

IM

BM

SC

TM

IM

BM

SC = Shear connector, CS = Concrete Slab, IM = Inclined MemberBM = Bottom Chord Member, TM = Top Chord Member

Fig. 2 Sectional x-x views of shear connector and CT structure

MATerIAL ModeLs

Concrete modeling

development of a model for the behavior of concrete is an important goal in the finite element modeling. concrete is a quasi brittle material and heterogeneous material unlike, steel which show similar trend in compression and tension testing. typical concrete stress strain curve in tension and compression from bangash25 is shown in fig. 3.

Peak compressive stressE0

Softening

Compression

Tension

Strain at maximum stress

σtu = maximum tensile strength of concrete

σcu

εo−ε+ε

εcu

fig. 3 typical stress strain curve for concrete

in compression, the stress-strain curve for concrete is linearly elastic up to about 30 percent of the maximum compressive strength. above this point, the stress


increases gradually up to the maximum compressive strength. After it reaches the maximum compressive strength σcu, the curve descends into a softening region, and eventually crushing failure occurs at an ultimate strain εcu. The stress values corresponding to strain values for concrete are plotted in fig. 4. in tension, the stress-strain curve for concrete is approximately linearly elastic up to the maximum tensile strength. after this point, the concrete cracks and the strength decreases gradually to zero as shown in fig. 5.

Series1

Stress vs Strain (compression)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

0.0000 0.0010 0.0020 0.0030Strain

Stre

ss, M

pa

fig. 4 Stress strain behaviour in compression for m25 concrete

Stre

ss σ

t

Strain εtσut

σut

Failure point

Tension stiffeningcurve

fig. 5 Stress strain behaviour in tension

in the present investigation, the rebar option is not used due to minimum possibility of getting tension at the concrete portion and the preliminary study also supported this decision. anSyS requires the isotropic material properties for the concrete and input data are given below.

Ultimate uniaxial compressive strength (ecu) = 25 n/mm2

The Elastic modulus (Ec) = 5000Fc = 25000 n/mm2

Poisson’s ratio (ν) = 0.18

The ultimate uniaxial tensile stress normally considered between 8 to 12 percent of compressive strength. in this investigation, the tensile strength is adopte as 10% of compressive strength i.e. 2.5 mPa. The shear transfer coefficient β, represents conditions of the crack face. the value of βt ranges from 0.0 to 1.0. the value 0 represents the smooth crack which is the complete loss of shear transfer and 1 represents a rough crack which is no loss of shear transfer. the value of βt used in the finite element model is 0.27.

ANALyTICAL INVesTIGATIoN oN THe eFFeCT oF sHeAr CoNNeCTor

Present investigation is carried out on square-on-square type double layer composite and non-composite space structure. the 20 m span space structures with 50 mm thickness of slabs were examined for 25 mm, 50 mm height of shear connectors. cross sectional area of 8mm diameter rod and the properties of mild steel are given as the input parameter for the linK8 element. the space structure modeling investigations are carried out on 10 m and 20 m span with five cases. The five cases are (1) steel space structure (2) composite space structure with full shear interaction (Concrete slab nodes directly attached to the steel nodes) (3) composite space structure with minimum / no shear connector (Concrete slab nodes are attached only at steel end corner nodes and no contact at intermittent steel nodes) (4) composite space structure with 25 mm shear connector and (5) composite space structure with 50 mm shear connector. The constant grids size of 2 m x 2 m with depth of 1.5 m and supported at four corner nodes were assigned for 20 m span. the members are assigned the properties of the tubular section which is arrived from the initial analysis is carried in the developed software in conjunction with the standard design module. the critical load is assessed for the combination of imposed load, dead weight of space structure and the wind load for chennai, india as per iS 875-part 326. the loads are applied at the top chord nodes for steel space structure and at the top of the concrete slab for composite space structure. the top, bottom and inclined members of the space structure were modeled using PiPE 16 elements. the concrete slab of 50mm thickness was modeled using


Solid 65 element. the load is calculated based on the participating panel area and applied as a uniformly distributed pressure as shown in figs. 6 and 7.

fig. 6 ct with uniformly distributed pressure load

fig. 7 typical view of lateral load on composite space structure

The finite element analysis carried out in ANSYS for the composite and non-composite space frame structures. The maximum downward deflection and the stresses in the concrete were obtained. in the post processing, the maximum deflection and the Minimum principle stress (Compressive stress) in concrete for the composite space structure with 25 mm length of shear connector are shown in figs. 8 and 9 respectively. the post processing resultant plot for the non-composite space structure and the composite space structure without shear connectors are presented in figs. 10 and 11.

Fig. 8 Deflection of CT with 25mm height shear connector

fig. 9 Principle compressive stresses of ct with 50mm connector

fig. 10 Principle compressive stresses of ct without shear connector


Fig. 11 Principle stresses for CT( The maximum comp. stress = 2.9 MPa)

eXPerIMeNTAL INVesTIGATIoN

In addition to the analytical study, experiments were conducted on steel space truss and steel concrete composite space trusses. both the structures were tested for the service load / design load, to calibrate the nonlinear finite element analysis results. The dimension of shear connector used in the analysis is used to simulate the actual as shown in fig. 12.

Square steel plate Metal sheeting

NodePipe

T type shear connector

Sheet for placing concrete

10mmBolt

fig. 12 typical view of shear connector

The first test was carried on steel space structure with double layer square on square type with a grid size of 1 m x 1 m and the second test was carried out on a steel concrete composite double layer square on

square space truss with a grid size of 1 m x 1 m. The members are developed from 26.9 mm diameter pipe section. the thickness of the concrete slab is proposed here with 100 mm. to maintain the same strength of 25 n/mm2 used in the analysis, the concrete slab is proposed with M20 concrete mix design. The average cube test results of concrete with M20 mix design is shown about 25 n/mm2, which is closer to the concrete strength used in the analysis. the steel space truss is assembled in ground and lifted and welded with top of the corner support columns. the solid spherical node is connected with supports and to other pipes and nodes.

Load setup for testing steel space truss

it was decided to apply a point load at the central node of the space truss system. for this, a loading arrangement was temporarily made with cradle type which hangs from bottom chord central node as shown in fig. 13. the steel space truss is tested to the load which is lower than the service load for re using the same truss for the construction of composite space truss. the steel dead weights and concrete slabs dead weights are weighed and placed over the cradle for loading the space structure. after testing the steel space truss, the concrete slab is cast over the concrete. the depth of concrete is maintained as the depth of shear connector.

Concrete slabs for dead weight

fig. 13 loading setup for testing

resULTs ANd dIsCUssIoN

The preliminary analysis shows a maximum compressive stress of 2.9 n/mm2 and minimum compressive stress of 0.6 n/mm2 at the center span of concrete element. the effects of shear connector with different length in the composite space structure are presented in table 1.


tablE 1

fEa rESultS for nct and ct WitH diffErEnt lEngtH of SHEar connEctor

10m span composite space frame

S.no type of truss load case Weight of steel, kn

central vertical deflection, mm

Stiffnesskn/mm

Deflection reduction

Stiffness increase

compared with nct, %1 nct dl + ll+Wl 9.488 9.405 42.3 - -2 ct without shear connector dl+ ll+Wl

8.245

8.817 45.37 6.25 6.67

3 ct with 25 mm height shear connector dl+ ll+Wl 8.178 48.91 13.05 15.0


5 ct, concrete node connected directly to steel dl+ll +Wl 7.638 52.37 18.79 23.14

Deflection Increase (%)

Stiffness Reduction (%)

compared with ct, concrete node connected directly to steel

6 ct without shear connector dl+ ll+Wl

8.245

8.817 45.37 15.44 17.18



20m span composite space frame

S.no type of truss load case Weight of steel, kn

central vertical deflection, mm

Stiffness kn/mm

Deflection Reduction (%)

Stiffness Increase (%)

compared with nct, %1

nct

dl

90.87

5.7 - - -2 ll 52.1 13.95 - -3 dl+ll 58.02 14.08 - -4 dl + ll+Wl 60.8 13.43 - -5

ct, concrete node connected directly to steel

dl

78.54

22.45 37.47 - -6 ll 20.1 36.0 159.2 258.17 dl+ll 42.65 36.77 36.0 261.28 dl+ll +Wl 41.62 37.66 26.86 280.4

-

Deflection Increase (%)

Stiffness Reduction(%)

compared with ct, concrete node connected directly to steel

9 ct without shear connector dl+ ll+Wl

78.54

52.8 29.68 26.86 21.19




the result clearly shows the effectiveness of composite slab compared to the steel space structures. the effect of shear connector in the 10 m span is low compared to the 20 m span. The deflection reduction in composite truss with 50 mm shear connector compared to steel space truss is about 19 percent for the 10 m span and about 28 percent for the 20 m span. in the similar way, the increase in stiffness of composite truss with 50 mm shear connector compared to steel space truss is about 23.67 percent for the 10 m span and about 142.51 percent for the 20 m span. the results can interpretive that the composite action is more effective in the larger spans than the shorter spans. the steel saving due to composite action is negligible in 10 m span and the 20 m span saves about 12.5 kn which is about 16 percent. the results can interpretive that the composite action in the composite space truss is more effective in larger spans than the shorter spans.

The increase of deflection in composite space structure with 50mm shear connector is about 5 percent compared to the composite truss with rigidly connected slabs. The increase in deflection of composite space truss with 25 mm length of shear connector is about 15.62 percent for 20 m span and about 7 percent for 10 m span compared to the concrete slab directly connects with the top individual bays nodes. the increase in the deflection due to lack of integrity between top node and concrete of composite space structure without shear connector shows about 27 percent for 20 m span and about 16 percent for 10 m span. this increase in deflection is due to the deficiency in shear connector interaction with respect to depth of concrete. also it is observed that the stiffness of composite truss is also affected with the length of shear connector used in the model. to compare and verify the mathematical modeling mechanism of steel space structure and composite space structure, the steel space truss and composite space structure were tested. the composite truss used the shear connector length equal to the concrete slab depth. The analytical and experimental results of composite space tress are compared and shown in fig. 14.

The analytical test results and the experimental results are promising each other with about 5 percent difference. the test results of composite space structure showed about 250 percent increase in stiffness due to

the composite action for the service load. the results show it’s evident for the modeling techniques chosen for the steel concrete composite structure. the 50 mm length of shear connector shows better performance for the composite space structure with 50 mm concrete slab. from the results, it is inferred that the composite space structure with shear connector height same as that of concrete slab height shows better performance.

Composite truss results comparison

02468

101214

0 0.1 0.2 0.3 0.4 0.5 0.6Deflection, mm

Load

, kN

/m2

Analytical-centernodeAnalytical-edgenodeExperimental-centernodeExperimental-edgenode1Experimental-edgenode2

Fig. 14 Load deflection comparison of composite space structure

CoNCLUsIoN

1. the composite space truss with shear connector length is equal to depth of concrete slab shows similar behaviour of concrete slab firmly attached to the top node. the reduction in the length of shear connector shows reduction in the performance.

2. the composite action is more effective and efficient in composite space structure for longer spans compared to shorter spans.

3. The deflection reduction in composite space structure is about 19 percent for the 10 m span and about 28 percent for the 20 m span compared to steel space structure.

4. the stiffness of composite space structure is about 23.67 percent for the 10 m span and about 142.51 percent for the 20 m span compared to steel space truss. the trend shows that the percentage of increase in stiffness is greater value for the span higher than the 20 m span.

5. the results of composite space structure showed about 250 percent increase in stiffness due to the composite action for the service load without considering the dead weight.


ACKNowLedGeMeNT

this paper is being published with the kind permission of director, cSir, SErc, chennai, india.

reFereNCes

1. Hanaor A., Marsh C. and Parke G.A.R., “Modification of double layer grids: over view”, Jl. of Struct. Engg., Vol. 115, no. 5, 1989, pp 1021–1037.

2. Schmidt l.c., morgan P.r. and Hanaor a., “Ultimate load testing of space trusses”, Jl. of Struct. Engg. Div., aScE, Vol. 108, no. 6, 1982, pp 1324–1335.

3. malla r.b. and Serrette r.l., “double layer grids: review of static and thermal analysis methods”, Jl. of Struct. Engg., aScE, Vol. 122, no. 8, 1996, pp 873–881.

4. Koh c.g., Swaddiwadhipong S. and lee S. L., “Collapse load of an aluminum hexagonal assembly of space frame members”, Intl. Jl. of Space Structs., Vol. 6, no. 1, 1991, pp 47–52.

5. Hiyama y., ishikawa K., Kato S. and okubo S., “Experiments and analysis of the post buckling behaviour of aluminum alloy double layer space grids applying ball joints”, Struct. Engg. and Mech., Vol. 9, no. 3, 2000, pp 289–304.

6. Han Q.H. and liu X.l, “ultimate bearing capacity of the welded hollow spherical joints in spatial reticulated structures”, Engg. Structs., Vol. 26, no. 1, 2004, pp 73–82.

7. Fulop A. and Ivanyi M., “Experimentally analyzed stability and ductility behaviour of a space-truss roof system”, Thin-Walled Structs., Vol. 42, 2004, pp 309–320.

8. agerskov H., “optimum geometry design of double layer space trusses”, Jl. of Struct. Engg., Vol. 112, no. 6, 1986, pp 1454–1462.

9. Chu H.S., “Analysis and experimentation of composite space slab-grid structures”, Proc. of 3rd Intl. Conf. on Space Structs., ed., Elsevier applied Science, london, 1984, pp 192–195.

10. Hanaor a. and Schmidt l., “Space truss studies with force limiting Devices”, Jl. of Struct. Engg. Div., aScE, Vol. 106, no. 11, 1980, pp 2313–2329.

11. Hanaor a., levy r. and rizzuto n., “investigation

of Prestressing in double-layer grids”, Proc. of the IASS Symposium, osaka, Vol.3, 1986, pp 73–80.

12. Hanaor A. and Levy R., “Imposed lack of fit as a mean of enhancing space truss design”, Space Structs., Vol. 1, no. 3, 1985, pp 147–154.

13. murtha-Smith E.a., “alternate path analysis of space trusses for progressive failure”, Jl. of Struct. Engg., aScE, Vol. 114, no. 9, 1988, pp 1978–1999.

14. El-Sheikh a., “Effect of force limiting devices on behaviour of space trusses”, Engg. Structs., Vol. 21, 1999, pp 34–44.

15. El-Sheikh a., “new space truss system - from the concept of implementation”, Engg. Structs., Vol. 22, 2000, pp 1070–1085.

16. Smith E.A., “Space truss nonlinear analysis”, Jl. of Struct. Engg., aScE, Vol. 110, no. 4, 1984, pp 688–705.

17. El-Sheikh A. and EL-Bakry H., “Experimental Study of New Space Truss System”, Jl. of Struct. Engg., Vol. 122, no. 8, 1996, pp 845–853.

18. El-Sheikh A. and McConnel R.E., “Experimental study of behaviour of composite space trusses”, Jl. of Struct. Eng.g, Vol. 119, no.3, 1993, pp 747–766.

19. El-Sheikh a., “Sensitivity composite and non-composite space trusses to member loss”, Intl. Jl. of Space Structs., Vol. 9, no. 2, 1994, pp 107–119.

20. El-Sheikh a., “Sensitivity of the space trusses to member geometric imperfections”, Intl. Jl. of Space Structs., Vol. 2, no. 7, 1995, pp 540–550.

21. El-Sheikh a. and Shaaban H., “Shear interaction between space trusses and timber boards”, Jl. of the Intl. Association for Shell and Spatial Structs., Vol. 38, no. 3, 1997, pp 155–164.

22. lakshmikandhan, K.n., Senthil, r. and Jatin,E., “comparative Study on steel Space frame Structures with Different Angle of Inclinations”, Nat.Conf. for Res. Scholars, acE, Hosur, india, 2005.

23. lakshmikandhan, K.n., Senthil, r., arul Jayachandran, S., Sivakumar, P. and ravichandran, r., “Study on the Effect of concrete Slab thickness on the Behaviour of Steel Space Structure”, Steel in Construct., INSDAG, 2009, Vol. 10 (1), pp 1–12.

24. lakshmikandhan, K.n., Senthil, r., arul


Jayachandran, S., Sivakumar, P. and ravichandran, r., “Parametric studies on the behaviour of steel and composite space structures”, Intl. Jl. of space Structs., 2010, Vol. 25, no.3, pp 169–183.

25. bangash m.y.H., “Concrete and Concrete Structures: Numerical Modeling and Applications’, 1st Edn., Elsevier Science Publishers ltd., 1989, london.

26. iS 875 – 1987, “Code of practice for design loads (other than earthquake) for buildings and structures - Part 3 Wind Loads”.

27. andrade S.a.l., Vellasco P.c.g.S. and Silva J.g.S., “tubular space trusses with simple and reinforced end-flattened nodes - an over view and experiments”, Jl. of Construct. Steel Res., Vol. 61, 2005, pp 1025–1050

28. lakshmikandhan K.n., Senthil r., arul Jayachandran S., Sivakumar P. and

ravichandran r., “comparative study on steel and concrete composite space structures”, Jl. of Struct. Engg., Vol. 37, no. 3, 2010, pp 180–187.

29. iS 800 - 2007, “Indian standard code of practice general construction in steel”, Third Revision.

30. iS 456 – 2000, “Indian Standard code of practice for plain and reinforced concrete”.

31. iS 1161- 1998, “Indian Standard for steel tubes for structural purpose – specification”.

32. Sebastian W.m., “collapse consideration and electrical analogies for statically indeterminate structures”, Jl. of Struct. Engg., aScE, Vol. 130, no. 10, 2004, pp 1445–1453.

(Discussion on this article must reach the editor before March 31, 2014)

Investigation on the effect of shear connector in composite space structures

Documents

Transcript of Investigation on the effect of shear connector in composite space structures