带热障涂层气冷叶片孔边局部应力分析

The stress distributions of the thermal barrier coating-substrate system with a hole under thermal mismatch were calculated using finite element method. Calculation results indicated that the interfacial normal/shear stress concentration occurred at the edge of the film hole, and higher circumferential stress existed near the edge of the hole. The coating near the hole edge was prone to cracking and spalling. The effects of the thickness of the ceramic layer, the outer diameter of the model, the thickness of the oxide layer, the hole diameter, and the temperature distribution on the local stress near the hole edge were calculated and analyzed. Results revealed that the region with interfacial normal and shear stress became larger while the thickness of the ceramic layer increased. The outer diameter of the sub-model, which was used to calculate the stress near the edge of the film hole, should be greater than the sum of four times of the ceramic layer’s thickness plus half of the diameter of the hole. Under the cooling condition, the interfacial normal and shear stress increased with the thickness of the oxide layer. At high temperature, the circumferential stress at the edge of the ceramic layer near the hole decreased with the diameter of the hole. The interfacial stress and circumferential stress near the hole edge increased in the case of non-uniform temperature distribution.