The effect of drilling-induced delamination on tensile strength and prediction of residual strength of carbon fiber-reinforced polymer laminate

Abstract

An energy-based continuum damage mechanics model was employed to investigate the effect of drilling-induced delamination on tensile strength of carbon fiber-reinforced polymer laminates and the residual strength was predicted. The decrease in tensile strength caused by delamination was investigated in detail by a finite element method (FEM) model. Experiments were also conducted to validate the numerical results. The drilling-induced delamination was measured with ultrasonic C-scan technique and modeled as deletions of corresponding cohesive elements in the FEM model. Different sizes of delamination zones were investigated and the predicted strengths were compared with experimental results. The FEM model showed that the decrease in strength is mainly caused by early failures of outer plies. Good correlation between numerical simulations and experimental results was also obtained.