A new 3D continuous-discontinuous heat conduction model and coupled thermomechanical model for simulating the thermal cracking of brittle materials

Abstract

This paper proposes a new 3D continuous-discontinuous heat conduction model to consider the thermal resistance effect of cracks and dynamic crack propagation during heat transfer. Combining this heat conduction model and the finite-discrete element method (FDEM), we construct a coupled thermomechanical model for solving thermal cracking problems in brittle materials. The mechanical fracture calculation utilizes virtual joint elements between adjacent solid elements for fracture simulation. On the other hand, virtual joint elements are not included in the heat conduction model to improve numerical efficiency. When new cracks are generated, the node sharing relationship is dynamically updated in the heat conduction calculation to consider the thermal resistance effect of cracks. In this study, the proposed models are verified by simulating heat transfer, coupled thermomechanical, and thermal cracking problems in brittle materials. The numerical simulations are consistent with analytical solutions, and a complex thermal crack process can be realistically captured. These numerical examples verify the correctness of the proposed models, which can be powerful tools for solving heat transfer, coupled thermomechanical, and thermal cracking problems in brittle materials.