Modeling Interlaminar Shear Crack-Jump Phenomenon in Fiber-Reinforced Polymer Composites

This paper discusses the simulation technique for the development of a validated finite element model to capture the stable shear crack-jump phenomenon in carbon fiber-reinforced polymer composite laminates. The interlaminar cracking process is characterized using a 16-ply unidirectional ([0]16) end-notch flexure (ENF) specimens. Complementary FE models of the test setup are developed to capture the mechanics of the observed interlaminar crack-jump phenomenon. The cohesive interface response is represented by a damage model with bilinear traction-displacement softening law. Close comparison of measured and FE-predicted load-central deflection response of the beam specimen serves to validate the FE model for the stable shear crack-jump. FE simulation predicts an early onset of damage at the interlaminar crack front corresponding to 13.4 pct. of the maximum deflection at fracture. The mechanism of stable crack-jump is described by the characteristic evolution of the interface damage parameter, and quantified by the damage dissipation energy.