Experimental and Numerical Investigation on Bending Capacity of Steel- concrete Composite Truss Girder

This article presents an experimental investigation on the bending capacity of steel-concrete composite truss girder (SCCTG). Four full-scale specimens named CB1, CB2a, CB2b and CB3 respectively, are tested and numerical analyzed. Stress distribution, load-displacement relationship, load-slip relationship and ultimate bending capacity of SCCTGs are investigated. The results show that SCCTG follows plane section assumption on the whole. SCCTG has a higher ultimate bearing capacity and good performance of deformation. Concrete slab and the steel truss can work together better using denser studs. In elastic stage, the effective width of the SCCTG flange plate remains the same with negligible variation. While in plastic stage, the effective width increases. Tests also prove that there is obvious shear lag effect in the concrete compression flange. Three-dimensional numerical model by finite element package ABAQUS is established to examine the bending behaviour of SCCTG. Hopefully, an acceptable correlation has been observed between the analytical and experimental results. There is obvious shear lag effect in the concrete compression flange. Shear lag should be paid great attention when designing and calculating the bearing capacity and deformation of SCCTG.