Residual compressive strength of composite laminates af ter low-velocity impact

The compressive failure tests were carried out on the composite laminates af ter low velocity impact dam-
age to study compressive failure mechanisms of laminates af ter low velocity impact damage. The effects of impact energy on the f ront surface dent depth , back surface resin crack length , damage area and residual compressive st rength were studied. Based on the experiment , a reduced stiffness inclusion model was developed to predict the residual compressive st rength of composite laminates af ter low velocity impact . In this model , the damage was considered as a soft elliptical zone of the material . A hybrid st ress finite element with an arbit rary elliptical inclusion for anisot ropic plates was programmed to compute the stress distribution. The point st ress criterion was used to determine whether the post-impact laminates are compressed to failure or not . Good agreement between predicted residual compressive st rength and experimental result s is obtained.