On the suitability of a 3D discrete element method to model the composite damage induced by thermal expansion mismatch

The paper aims to investigate the suitability of a 3D discrete element method to simulate the thermal-induced damage in composite materials using a cohesive beam model. First, we aim to predict the elastic behavior of continuous material in the case of a homogeneous medium. For that purpose, mechanical tests are performed on a representative pattern and some properties of continuous materials are discussed. Then, we investigate a model of thermal expansion in the context of a homogeneous material to simulate its thermoelastic behavior. The case of a single-inclusion composite is also discussed and some comparisons are done with the finite element method (FEM) and analytical formulations. Damage effects and interfacial debonding are taken into account in order to model the thermal-induced damage due to the thermal expansion mismatch. Finally, a similar study is applied in the context of multi-inclusion composite. From a quantitative standpoint, discrete element results in terms of coefficient of thermal expansion and stress and strain fields are in good agreement with the predictions given by FEM and analytical formulations. Besides, from a qualitative standpoint, the present work exhibits suitable damage modes in accordance with thermal conditions.