A complete phase-field fracture model for brittle materials subjected to thermal shocks

TL;DR

This paper introduces a comprehensive phase-field fracture model for brittle materials under thermal shocks, capable of predicting crack initiation and propagation across various thermo-mechanical scenarios with high accuracy.

Contribution

The work presents a complete, coupled thermo-mechanical phase-field fracture model that independently specifies material properties and captures diverse fracture phenomena.

Findings

Successfully predicts crack patterns in glass during quenching

Reproduces crack behaviors in infrared-irradiated ceramics

Explains fracture transitions in ceramic pellets under power pulses

Abstract

Brittle materials subjected to thermal shocks experience strong temperature gradients that in turn give rise to mechanical stresses that can be large enough to induce fracture. This work presents a complete model for phase-field fracture for coupled thermo-mechanical problems, wherein the bulk material properties, the material strength, and the fracture toughness are specified independently. The capabilities of the model are assessed across a wide span of scenarios in thermo-mechanical fracture, from the propagation of large pre-existing cracks to crack nucleation under spatially uniform states of stress. In particular, we revisit the controlled quenching of glass plates, and demonstrate how the model captures experimentally observed crack patterns across a range of thermal loads. Ceramic disks subjected to infrared radiation are also examined, with the model reproducing both straight cracks in notched specimens and branching in intact specimens. Finally, ceramic pellets subjected to rapid power pulses are examined, with the model explaining experimental transitions from intact to fractured pellets and the important role of material strength. The results demonstrate that the complete phase-field model unifies the treatment of distinct fracture scenarios under thermal shock, surpassing classical approaches and enabling more reliable prediction of brittle fracture in extreme environments.