Impact damage resistance of graphite/epoxy laminated composites

Damage in graphite/epoxy laminated composites resulting from low‐velocity impact was studied. The impact damage mechanisms and mechanics were first investigated by adopting the impactors with a line‐nosed head from which the damage was simplified from a complicated three‐dimensional pattern to a two‐dimensional one. Based on the results of the line‐loading impact study, a model was developed for predicting the impact damage in the materials resulting from point‐loading impact. The model consists of a stress analysis for calculating transient dynamic stresses during impact and a failure analysis for predicting the extent of delaminations resulting from the impact. A computer code, “3DIMPACT”, was developed based on the model during the investigation. The predictions from the code agreed fairly well with the test data.