A coupled 3D thermo-mechanical peridynamic model for cracking analysis of homogeneous and heterogeneous materials

This paper proposes a variable timestep-strategy that can speed up the peridynamic modeling of thermomechanical cracking in both homogeneous and heterogeneous materials. A piecewise continuous time-step variation function is incorporated into the peridynamic framework that dynamically adjusts the time-step size, which ranges from a small value to a maximum value that remains below the critical stable time-step. The advantages of this variable timestep strategy are threefold: (1) The exceptional computational efficiency of this approach is mainly manifested in enabling peridynamic simulation that is 20 times faster compared to that employing a constant time step; (2) Taking advantage of the proposed method, both two- and three-dimensional peridynamic modeling of thermomechanical deformation and crack propagation has been demonstrated to be of great accuracy and robustness; (3) Facilitated with this variable timestep strategy, we achieve a remarkable advancement in peridynamics to capture intricate 3D crack patterns with complex topological structures in homogeneous specimens subjected to water quenching. Furthermore, the effects of the temperature difference, specimen geometrical configurations and the initial water entry velocity on the crack patterns of the specimens under water quenching are systematically explored.