Polycrystalline materials are widely utilized in engineering fields. In this study, peridynamic (PD) models are developed for the first time in the literature to investigate thermally-induced fracture phenomenon for cubic polycrystals and ceramic made of different materials. After validating the current model, the influences of the grain size, grain boundary strength and composition of the materials on the fracture behavior are analyzed. Two different types of pre-existing cracks, i.e. vertical and horizontal, are considered. The effect of grain size is much more obvious for ceramic materials and crack branching is observed for both vertical and horizontal crack cases. Grain boundary strength has a significant influence on crack behaviour. For weaker grain boundaries intergranular fracture pattern is observed whereas for stronger grain boundaries transgranular crack pattern is more dominant. Crack branching is much more significant when the silicon carbide ratio is higher due to the difference in coefficients of thermal expansion of two different materials. By comparing with the reference results available in the literature similar fracture features are obtained.

多晶材料广泛用于工程领域。在这项研究中，在文献中首次开发了绕动力学（PD）模型，以研究由不同材料制成的立方多晶和陶瓷的热致断裂现象。在验证了当前模型之后，分析了晶粒尺寸，晶界强度和材料组成对断裂行为的影响。考虑了两种不同类型的现有裂缝，即垂直裂缝和水平裂缝。陶瓷材料的晶粒尺寸影响要明显得多，在垂直和水平裂纹情况下都观察到裂纹分支。晶界强度对裂纹行为有重要影响。对于较弱的晶界，观察到晶间断裂模式，而对于较强的晶界，跨晶裂纹模式更占优势。当碳化硅比例较高时，由于两种不同材料的热膨胀系数不同，裂纹分支更为明显。通过与文献中的参考结果进行比较，可以获得类似的断裂特征。