A coupling model of peridynamics and finite element method is proposed to study the interfacial delamination influenced by vertical crack density in thermal barrier coating (TBC) systems. Specifically, the progressive failure progress under static and fatigue loads in TBCs, including vertical cracks propagation, the evolution of vertical cracks to interfacial cracks, and interfacial delamination, is simulated by the proposed model. The difference between static failure mechanism and fatigue failure mechanism of TBCs is numerically elucidated. The simulated fracture morphology is in good agreement with the experiential observation. In both static and fatigue loads, a higher vertical crack density is found to correspond to a shorter delamination length, and there is no interfacial delamination when the vertical crack density is high enough. The results provide important insight of vertical crack density on interfacial delamination, and the durability of TBCs can be enhanced by ensuring an appropriately high vertical crack density.

提出了近场动力学和有限元方法的耦合模型来研究热障涂层（TBC）系统中垂直裂纹密度对界面分层的影响。具体来说，该模型模拟了热障涂层在静态和疲劳载荷下的渐进失效过程，包括垂直裂纹扩展、垂直裂纹到界面裂纹的演变以及界面分层。从数值上阐明了 TBC 的静态失效机制和疲劳失效机制之间的差异。模拟的断裂形貌与经验观察结果吻合良好。在静态和疲劳载荷下，较高的垂直裂纹密度对应于较短的分层长度，并且当垂直裂纹密度足够高时不会出现界面分层。结果提供了关于界面分层的垂直裂纹密度的重要见解，并且可以通过确保适当高的垂直裂纹密度来增强热障涂层的耐久性。