The effect of multiple impact damage on the residual compressive strength of composite structures

This paper focuses on the problem of multiple impact damage in composite laminates and describes the static compressive response of AS4/350 1-6 carbon fibre/epoxy laminates containing a single or multiple impact damage sites. The interaction effect between the multiple impacts was investigated as a function of spacing and orientation with respect to the loading direction. Damage growth during monotonic loading to failure was observed using shadow moire fringe techniques. Thermoelastic images as well as residual compressive strength results reveal that, for the various configurations of multiple impact damage in composite laminates investigated, little interaction between the impact sites was observed.