Numerical modelling of the compression-after-impact performance of a composite sandwich panel

A numerical model for the quasi-static indentation and compression-after-impact behaviour of a composite sandwich panel is presented, using cohesive surfaces for interlaminar damage prediction. Intra-laminar damage and core crushing is also included. The models show generally good agreement with experimental results for residual strength, performing best when two cohesive surfaces are used in the impacted skin, but tend to over-estimate the undamaged panel strength. Damage extent predictions from the indentation phase of the analysis are often quite poor, but do not necessarily correlate with the accuracy of the strength estimates. The model provides a promising basis for further development.