Phase-field simulation of thermal cracking with length-scale insensitive degradation functions

The present paper applies a length-scale insensitive degradation function to accelerate the simulation of thermal cracking problems. The solid deformation, damage evolution, and heat conduction process are coupled. The solid is treated as a linear elasticity, whose strain is composed of the mechanical strain and the thermal strain induced by thermal expansion. The cracks in solids are represented by the diffusive phase-field variables. The length-scale insensitive degradation function has been employed to decouple the length scale of the phase-field length scale and that of the physical process area, which alleviates the meshing burden of the phase field. The numerical results of our ceramic examples of interest are in good agreement with the experimental results, and this work may have important implications for predicting thermal cracking problems on large scales.