Prediction of debonding growth in two-dimensional RVEs using an extended interface element based on continuum damage mechanics concept

In the present study, a new interface model based on continuum damage mechanics (CDM) is developed to investigate the fiber-matrix interfacial debonding in the composite material. This model differs from Voronoi cell finite element and cohesive zone element method. To this purpose, a 2D classical elasticity formulation with non-interactive strength-based criteria and complex variable method with non-interactive energy-based criteria are applied for the analysis of the debond onset and propagation in an RVE with a single fiber, respectively. Then, the CDM approach is used to bridge between analytical and numerical methods. The developed model based on CDM is implanted into ANSYS commercial software to compare the accuracy of the proposed method with the obtained results by the cohesive zone model in RVEs containing single and multiple fibers. The admissible matching between the obtained stress-strain responses reveals the capability of the proposed approach to predict the fiber-matrix debonding as a primary damage mode in composite materials.