Behaviour of a Sacrificial Cladding with Foam Concrete-Filled Square Tubes under Impact Loads

In this paper, a new sacrificial cladding with foam concrete-filled square tubes (FCFST sacrificial cladding) was developed for dissipating impact energy. The impact experiment was conducted on the FCFST sacrificial claddings using a drop hammer impact experiment system, and the finite element simulation analysis was performed using the explicit nonlinear program LS-DYNA. The deformation modes, force-displacement responses and energy absorption performances of the FCFST sacrificial claddings were discussed. The results indicated that the impact responses of the FCFST sacrificial cladding could be classified into four stages, and the energy absorption performance could be enhanced by increasing the contact area between the sacrificial cladding and impactor. Foam concrete-filled tubes that underwent obvious plastic deformation dissipated more impact energy than other parts of the sacrificial cladding, and three deformation modes could be identified in theses tubes. Furthermore, the effects of the thickness ratio of the top plate to tube, width-to-thickness ratio of the tube and impact location on the impact behaviour of the FCFST sacrificial cladding were numerically studied. It was found that decreasing the thickness ratio of the top plate to tube could enhance the energy absorption performance of the FCFST sacrificial cladding. However, the impact location was found to have little effect on the energy absorption unless it was close to the edge of the sacrificial cladding.