Study on fracture characteristics of 3D-ILC brittle solids under high-temperature loading in three-point bending

This study predicts the mechanical behavior and crack propagation of rock-like materials under high- temperature conditions in deep engineering applications through experimental and numerical simulations. The 3D-ILC method was utilized to induce three-dimensional fissures in a semi-circular disk specimen. The threepoint bending test following high-temperature cooling was conducted to analyze the failure mode and fracture morphology. By integrating the maximum tensile stress criterion, M-integral method, and finite element analysis, a thermomechanical simulation of three-dimensional crack propagation is conducted. This reveals the relationship between the stress intensity factor at the crack tip and the relative circumference of the crack front, enabling a detailed visualization of the crack propagation path. The results show that the horizontal single crack extends in a "U"-shaped pattern with increasing temperature, while dynamic fracture occurs along the crack center during the three-point bending test. At high temperatures, crack propagation in the specimens is primarily governed by Mode I, whereas in the three-point bending tests, crack propagation transitions through Modes I, II, and III. This study provides a robust framework for analyzing the mechanical behavior of rock-like materials under thermal and mechanical loading in deep engineering environments.