Three-dimensional frictional dynamic contact analysis for predicting low-velocity impact damage in composite laminates

The low-velocity impact and impact induced damage in composite laminates are studied in this paper by using the finite element technique. A three-dimensional (3D) dynamic contact model with friction is presented. The contact constraints of the model are described in the velocity field, instead of the displacement field as conventionally. This alternative description of the contact constraints may better satisfy the impenetrability condition and decrease the numerical oscillations in the computation. The sliding and friction, which are controlled by Coulomb friction law, are included in the contact-impact model. The semi-discrete finite element equation is solved by Newmark Algorithm with modifications based on the elastic wave propagation theory. An augmented Lagrange iteration with adaptive penalty is developed to ensure the convergence and the accurate solution of the contact problem. A technique for searching the contact point pair in 3D finite element analysis is proposed. Based on the results of contact-impact analysis, the damage predicting in composite laminates has been made. Numerical examples are given to demonstrate the validity and efficiency of the numerical algorithms and the computational strategies developed in this paper. (C) 2002 Published by Elsevier Science Ltd.