Finite element analysis of demountable steel-concrete composite beams under static loading

This paper investigates the innovative beam-slab connectors to enable steel-concrete framed structures to be made demountable. A computational simulation for determining the fundamental performance of the demountable composite beams with hollow core concrete slabs, profiled steel deck and bolted shear connectors is developed using the computational code ABAQUS. This numerical model was employed to compare the strength, stiffness and ductility of conventional composite beams utilising welded shear connectors with that of demountable steel-concrete beams utilising blind bolts. The bolted shear connectors not only overcome problems that prevent rehabilitation of existing composite beams with headed studs but also allow for the demountability in the composite beams. The adequacy of the developed computational models is evaluated by verifying the computational results against the corresponding experimental performance. The verification demonstrates that the computational simulations agree with the test performance. The numerical prediction indicated that the shear capacity of blind bolts used in demountable composite metal decking slabs is higher than that of welded connectors utilised in the conventional steel-concrete composite beams. It is found that the composite beams with bolted connectors can be made demountable up to a load of about 50% of the ultimate load which is greater than typical service loads. The strength of shear connectors obtained from the finite element models and experiments were compared with the predicted strength using Eurocode 4 and AS2327.1-2003. It appears that Eurocode 4 and AS2327.1-2003 provide the conservative solutions for the design of shear connector strengths.