A new method for compression after impact strength prediction of composite laminates

摘要

A new method todetermine the compression after impact (CAI) strength of composite laminates was presented.In this method,animpact damage zone was modeled as an eqivalent hole.The most outstanding characteristic of the method was that the simplification of the impact damage was based on the compressive failure mechanisms of impacted laminates.Such a simplification has not bee discussed in theliterature before.A technique was established for determining the shape and size of the equivalent hole.To the authors' knowledge,it is the first practical method for simplifying the impact damage as a hole,and also the present work was the first attempt to predict the CAI strength by modeling the impact damage as a hole.The stress distribution around damage was calculated using the complex potential method and the classical lamination theory.A lay-up independent failure criterion was used to predict CAI strength.The influence of damage area,impact energy,impactor shape and dimension,etc.on CAI strength can be essentially characterized by their effects on the damage width.The study provided a very simple and effective approach for CAI strength prediction compared with previous methods.