Finite Element Modeling and Analysis of Low Velocity Impact on Composite Structures Subject to Progressive Damage and Delamination

There has been growing interest to use composites in load carrying structures where high strength and light weight are of major concern, e.g., sports, automobiles and aircraft industries. Despite extensive research in the last two decades, mechanical behavior of composite structures subject to contact and impact loading is still not well understood. It is well known that composites are highly vulnerable to various modes of failure and damage due to impact/contact by foreign objects. Such impact/contact events are not only dependent on the material behavior but also on the dynamics of the structure. Although some of the currently available Finite Element (FE) packages are capable of simulating mechanical behavior of composite structures subject to impact, it requires extensive training and in-depth knowledge to obtain an adequate model with acceptable efficiency. Several nonlinear FE models have the ability to capture composite damage due to impact/contact including internal delamination or fiber/matrix failure. On the other hand, very few FE models are able to capture composite damage progression or material degradation. This work investigates different modeling techniques by analyzing their prediction of force-time history and force-indentation curve occurring in composite plates as a result of low velocity impact. The objective is to compare different techniques, both in model creation and impact response prediction, and to provide guidelines on selecting the most appropriate technique for a given impact situation.