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由于残余应力的作用是造成热障涂层失效剥落的主要因素之一,本工作采用不同幅值的正弦曲线来模拟粗糙度对陶瓷层(TBC)-结合层(BC)界面处残余应力分布的影响;以内聚力模型模拟TBC-BC界面,研究了在外加机械载荷作用下粗糙度对界面裂纹萌生和扩展的影响。结果表明,粗糙度对残余应力分布以及裂纹的形核与扩展有很大的影响。随着粗糙度的增大,陶瓷层和结合层靠近界面的波峰波谷处最大拉/压应力也增大。当施加一定拉伸位移载荷时,最大损伤与裂纹首先在幅值最小的波峰波谷处产生。
As the residual stress is one of the main factors that lead to the failure of the thermal barrier coating, the sine wave with different amplitude is used to simulate the distribution of residual stress in the interface between the ceramic layer (TBC) and the bonding layer (BC) The cohesion model was used to simulate the interface of TBC-BC. The effect of roughness on the initiation and propagation of interfacial cracks under the mechanical loading was also studied. The results show that roughness has great influence on the distribution of residual stress and the nucleation and propagation of cracks. With the increase of roughness, the maximum tensile / compressive stress of the ceramic layer and the bonding layer near the interface is also increased. When a certain tensile displacement load is applied, the maximum damage and crack are firstly produced in the crest valley with the lowest amplitude.