Finite element analysis of low-velocity impact damage in composite laminated plates

Matrix cracking and delamination are the most common damage mechanisms in laminated fiber reinforced composites due to low velocity impact. An approach to predict the initiation and propagation of damage in composite laminated plates is brought forward in this paper, which is based on contact constraint introduced by penalty function method. The potential delamination and matrix cracking areas are considered as cohesive zone and the damage process as contact behavior between the interfaces. A scalar damage variable is introduced and the degradation of the interface stiffness is established. A damage surface which combines stress-based and fracture-mechanics-based failure criteria is set up to derive the damage evolution law. The damage model is implemented into a commercial finite element package, ABAQUS, via its user subroutine VUINTER. Numerical results on (0(4), 90(4))s carbon-epoxy laminate plates due to transversely low velocity impact are in good agreement with experimental observations. (C) 2004 Elsevier Ltd. All rights reserved.