Quasi-static and dynamic behavior of sandwich panels with multilayer gradient lattice cores

The static/dynamic compressive performances of sandwich panels with density gradient lattice core were investigated by experimental and numerical methods. A three-layer stainless steel lattice sandwich panel was proposed, and the density gradient between core layers of the sandwich panels was achieved by varying the cross-sectional dimensions of truss bar of each layer. A large diameter Hopkinson pressure bar device was employed to carried out the dynamic impact experiment. The three-dimension finite element method was used to investigate the effects of gradient scheme of core layers and the impact velocity on the structural response. The results reveal that, there exists different failure mechanism between non-gradient lattice sandwich panels and gradient lattice sandwich panels, and the ABC gradient configuration is optimal due to its higher impact strength and better energy absorption capacity at a higher impact velocity which can buckle the truss bars of all layers of gradient lattice sandwich panel.