To overcome the limitations of widely used criteria, maximum principal stress and maximum tension stress, in simulating and evaluating thermal shock resistance of ceramics for 3-dimension (3D) problems, a temperature-dependent critical fracture energy density criterion was proposed based on the force-heat equivalence energy density principle for the 3D thermal shock fracture problems of ceramic materials in this paper. Taking advantage of the criterion and finite element method, the thermal shock behavior of water quenching of cuboid Al₂O₃ specimens with different temperature differences were simulated. The crack patterns of the simulation results were shown to be approximated in the experiments. Especially the essential features, the longitudinal main crack and crack branches, are embodied well in the simulation results. However, the thermal shock cracks obtained by using the criteria, maximum principal stress and maximum tension stress, failed to meet the experiments. The effects of water entry posture on thermal shock crack features revealed in the results confirm the efficiency of the criterion in 3D conditions of thermal shock fracture in this paper. Finally, the maximum temperature gradient, not maximum temperature difference, was found to be the main controlling factor which caused the fracture energy density to reach a critical value to produce thermal shock crack.

为了克服广泛使用的准则（最大主应力和最大拉应力）的局限性，在模拟和评估三维（3D）问题的陶瓷的耐热冲击性时，提出了一种基于温度的临界断裂能密度标准。本文针对陶瓷材料的3D热冲击断裂问题采用了等温能量密度原理。利用准则和有限元方法，对长方体Al ₂ O ₃进行水淬的热冲击行为模拟了具有不同温差的样本。实验结果表明，模拟结果的裂纹模式近似。在模拟结果中，尤其体现了基本特征，即纵向主裂纹和裂纹分支。然而，通过使用准则（最大主应力和最大拉应力）获得的热冲击裂纹未能满足实验要求。结果表明水进入姿势对热冲击裂纹特征的影响证实了该标准在3D热冲击断裂条件下的有效性。最后，发现最大温度梯度而不是最大温差是导致断裂能密度达到临界值以产生热冲击裂纹的主要控制因素。