Parametric Study of CFST Chord in Tubular Brace Truss to Full Scale Model Using FEA

— Concrete filled steel tubular truss (CFST truss) structures is a composite structures composed of CFST members as chords and steel tube members as braces are having expanded utilization in large-scale infrastructure constructions such as bridges, electricity towers, buildings etc. This CFST sections are formed by filling concrete into a hollow steel tube section and offers resistance to applied load through the composite action of steel and concrete. A concrete slab is usually provided on top of the CFST truss to form a hybrid CFST truss bridge structures. This paper thus presents a finite element analysis (FEA) modelling on CFST truss without concrete slab as well as hybrid CFST truss with concrete slab subjected to flexural loading, and then modelling a full scale Concrete filled double skin steel tubular (CFDST) truss bridge and analyse the structural response of the bridge. Before this the important parameters which influences the strength of the composite truss are also investigated, including effect of core concrete, behaviour of angle, type of chords, effect of shear span ,effect of plan curvature and effect of elevation curvature. A CFDST truss with 600 brace angle is best suited for the analysis of full scale model. A comparison on seismic performance of CFST and CFDST truss bridge are also investigated.