Experimental study on curved steel-concrete-steel sandwich shells under concentrated load by a hemi-spherical head

Abstract

Steel-concrete-steel (SCS) sandwich shells, which are combined with steel plates, concrete core and shear connectors, are usually applied as protective structures in the civil engineering. In this paper, nine curved SCS sandwich shells subjected to concentrated load by a hemi-spherical head were tested to obtain the failure characteristic, ultimate strength and load–displacement response. The finite element (FE) models of curved SCS sandwich shells were also established by using LS-DYNA. The accuracies of the FE models were verified by comparing the load–displacement curves, local and global deformation between the experimental results and FE predictions. The factors influencing the ultimate strength and deformation behavior of curved SCS sandwich shells were analysed, including concrete core and steel plate thickness, top to bottom steel plate thickness ratio and spacing of shear connectors. Through experiments and numerical simulations, three failure modes could be summarized. It was also found that increasing concrete core and top steel plate thickness and reducing the spacing of shear connectors could increase yield strength and ultimate strength of curved SCS sandwich shell. The increase of concrete core and steel plate thickness also led to higher energy absorption capacity; whereas, the spacing of shear connectors showed little effect on energy absorption capacity.