The evaluation of impact damage in a composite plate with a hole

This investigation has revealed the effect of a hole on the damage produced in the impact region and on failure in the vicinity of the hole. It is indicated from the investigation that the matrix damage is a typical character to represent the interaction between a remote impact region and a hole. A detailed comparison between the simulation (which uses the maximum stress and quadratic stress failure criteria) and experiment has been made for 0.59 J impact to a carbon/epoxy composite plate containing a hole. Both the simulation and the experiment show that there are two parallel matrix cracks between the impact point and the hole. From the simulation, one crack (originating crack) initiates at the point of impact and propagates towards the hole whereas the other crack (rebounding crack) initiates near the hole edge and propagates towards the impact centre. In addition two more predicted cracks emanate from the far side of the hole and one of them appeared in the experiment. It is shown that the cracks can be initiated by either tension or shear or a combination of both.