POST-IMPACT COMPRESSIVE STRENGTH OF SMALL COMPOSITE LAMINATE SPECIMENS

A miniature post impact compression test was used to study the technique for composite testing with a view to reducing the cost of testing materials. This test method can be used in a material developing phase. Based on experimental studies, a reduced stiffness inclusion model was developed to predict the residual compressive strength of composite laminates after the low velocity impact. In this model the damage was considered as a soft zone of the material. The damage zone was assumed to be circular. A finite element code with the 8-node 2D isoparametric element was programmed to compute the stress distributions. The point stress criterion was used to determine whether the post-impact laminates are compressed to failure or not. Good agreement between predicted residual compressive strengths and experimental results is obtained.