LAUSR

Abstract A finite element (FE) model is formulated in this paper to predict the impact induced delamination of fiber reinforced plastic (FRP) laminates by incorporating a traction-separation law into a recently developed progressive damage model. Strain rate effects are taken into account for the first time in the traction-separation law/cohesive element model so that delamination of FRP laminates subjected to impact by projectiles at different velocities can be predicted accurately. To validate the FE model a numerical study is conducted on the response of carbon fiber reinforced plastic (CFRP, graphite/epoxy) laminates under both low velocity and ballistic impact. Numerical simulations using the MAT162 model in LS-DYNA are also conducted so that a comparison can be made between the present model and the MAT162. Furthermore, parametric study is performed to assess the influences of strain rate, inter-laminar shear strength and ply angle on the impact induced delamination of CFRP laminates. It transpires that the present model predicts well the experiments in terms of delamination (failure) pattern, delamination area, load-displacement curve and residual velocity for both low velocity impact and high velocity perforation using cohesive elements when strain rate effects are taken into consideration. It also transpires that the present model is advantageous over the existing model such as the MAT162 model.