Simulation of Mixed-Mode I/II Debond Using VCCT and Cohesive Elements

Abstract

This paper presents a modelling strategy for the simulation of quasi-static mixedmode I/II debond propagation in a bonded unidirectional composite specimen configuration. The previous test data sets were re-examined to validate the modelling, i.e., measured debond lengths were assessed and updated based on a correlation between the stiffness and the debond length. The correlation was obtained via a series of two-dimensional (2D) finite element (FE) analyses with different debond lengths. With the resulting “effective” initial debond lengths, finite element (FE) analyses of mixed-mode debonding was carried out with the virtual crack closure technique (VCCT) and cohesive zone modelling (CZM). The performance of VCCT and cohesive elements in the debonding simulation was assessed for a mode mixity of 0.2. Good agreement in the load-displacement relationship was obtained between experimental and numerical results. Discussion on the test data evaluation and the modelling strategy over a wide range of mode mixities is presented.