On a discrete element method to simulate thermal-induced damage in 2D composite materials

The present contribution deals with a discrete element method to simulate thermal-induced damage in 2D composite materials. We consider a hybrid particulate-lattice model based on the equivalence between a granular system and a network of cohesive beam elements. This choice is mainly motivated by previous papers exhibiting its ability to model heterogeneous materials in which complex fracture phenomena occur. Our objectives are twofold. First, we aim to introduce a thermo-elastic coupling using a recently developed model of thermal expansion based on the dilatation of the beam element. Second, we are interested in studying the suitability of the discrete element method to model the thermal-induced damage due to thermal expansion mismatch. For that purpose, several preliminary studies are performed to verify the validity of the thermal expansion model in the context of continuous media. Then, damage effects and interfacial debonding are taken into account and the model is applied to the case of 2D metallic fiber composites with a brittle alumina matrix. Results exhibit the ability of the present approach to simulate the suitable damage mode as a function of thermal conditions. Besides, realistic failure patterns with radial propagations are obtained in the context of cracks opening.