ANALYSIS OF CRACK PATH INSTABILITIES IN A QUENCHED GLASS PLATE USING THE PHASE-FIELD COHESIVE ZONE MODEL

Cracks with unstable paths will appear in the glass during quenching. For different quenching speeds and temperatures, there will be linear, oscillatory and bifurcated crack paths. In this work, the phase -field cohesive zone model (PF-CZM) is adopted as the prototype model to address the problem of crack path instabilities in a quenched glass plate. Substituting the temperature field model into the phase field model, the thermal -mechanical coupling fracture problem is solved. The model accurately predicts different crack patterns in the quenched glass under different thermal shock densities. The variation of the crack tip positions and the crack propagating velocity are obtained. Several typical crack morphologies are simulated and analyzed, including linear, sinusoidal, semicircular and bifurcated cracks. The thresholds for crack propagation morphological variations are distinguished. Comparison with experimental data shows the efficiency and accuracy of the used phase -field model applied to thermal shock problems.