A New Definition of Peridynamic Damage for Thermo-Mechanical Fracture in Brittle Materials

A thermo-mechanical fracture modeling is proposed to address thermal failure issues, where the temperature field is calculated by a heat conduction model based on classical continuum mechanics (CCM), while the deformation field with discontinuities is calculated using the peridynamic (PD) model. The model is calculated using a CCM/PD alternating solution based on finite element discretization, which ensures the calculation accuracy and facilitates engineering applications. The original PD model defines damage solely based on the number of broken bonds in the vicinity of the material point, neglecting the distribution of these bonds. To address this limitation, a new definition of the PD damage accounting for both the number of broken bonds and their specific distribution is proposed. As a result, damage in various directions can be captured, enabling more realistic thermal fracture simulations based on a unified mesh discretization. The effectiveness of the proposed model is validated by comparing numerical examples with analytical solutions. Moreover, simulation results, including a thermal shock case with a transient temperature field, demonstrate the model's ability to aid in understanding the initiation and propagation mechanisms of complex thermal fractures.