An Analytical Method for Evaluation of Impact Damage Energy of Laminated Composites

Abstract : A higher order beam finite element is developed for dynamic response of beams subjected to impact of elastic spheres. Hertzian law is used to evaluate the contact force. A step by step finite difference method is employed to integrate the time variable. The finite elements are first evaluated for homogeneous isotropic beams and excellent results are found. Impact of glass- epoxy laminates are then considered. The total energy imparted from the projectile to the laminate is computed and compared with experimental data. Good agreement is found. The present finite element procedure also allows one to separate the vibrational energy from the damage energy which is to be related to the residual strength of the composite after impact.