Numerical study of mode I fracture toughness of carbon-fibre-reinforced plastic under an impact load

Abstract

The main objective of this work is, by using cohesive zone modelling, to compute the fracture toughness behaviour in mode I of unidirectional carbon-fibre-reinforced plastic subjected to an impact load at 4.7 m/s. To perform this task, double-cantilever beam specimens were simulated, with its opening displacement and crack propagation being assessed, as well as the evolution of strain rate through the test. Therefore, by plotting the crack propagation, it was possible to calculate the fracture toughness in mode I (GIC). A comparison of the numerical results with experimental tests previously performed by using a drop weight falling-wedge impact test equipment was made, allowing to infer that the numerical approach, based on a triangular cohesive zone modelling, is capable to predict the behaviour of such specimens under impact, accurately obtain GIC, and to determine the value of strain rate achieved through the test.