DELAMINATION IN CROSS-PLY LAMINATED COMPOSITE SUBJECTED TO LOW-VELOCITY IMPACT

Delamination due to low-velocity impact of simply supported graphite/e poxy cross-ply laminate beams and plates was investigated. Both quasis tatic and low-velocity impact testing were carried out in this study. For each loading condition, finite element analysis and experiments we re performed to study damage growth and distributions. The mode II ene rgy release rate for dynamic crack arrest G(IIa) was 75% less than the onset of crack propagation G(IIC). A quasistatic three-dimensional fi nite element analysis coupled with a G(II) greater-than-or-equal-to G( IIC) criterion was used for the onset of delamination propagation, and G(II) less-than-or-equal-to G(IIa) criterion was used to arrest the p ropagating crack and to estimate the delamination area. Delamination a rea determined by this method correlated well with the test results.