Experimental and numerical investigation of the effect of asymmetry on the residual strength of a composite sandwich panel

Asymmetric sandwich panels with skins of differing thickness are subjected to various degrees of damage via quasi-static indentation before compressive loading to failure. These are compared with panels with skins of equal thickness. The experiments show that the asymmetric panels experience an improvement in strength with small amounts of indentation compared with undamaged asymmetric panels, and for more severe damage, show greater residual strength than the symmetric panels. The two configurations are numerically modelled using Abaqus, including inter- and intra-laminar damage, and core crushing. The strength predictions from the models agree well with the experiments.