界面具有垂直裂纹的热障涂层的失效模拟

采用有限元分析软件ANSYS构造了一个在热生长氧化层（TGO）与陶瓷层界面具有一个垂直裂纹的纳米结构热障涂层的有限元模型。并计算了在热震过程中裂纹处的应力分布图，及裂纹尖端的应力场强度因子K1变化图。计算结果表明：裂纹处存在应力集中现象，且裂纹尖端的应力场强度因子K1在热障涂层热循环的冷却过程中随着时间的延长而减小，且在冷却最开始阶段，温度梯度变化最大，K1值也变化最大，裂纹在冷却的初始具有最大的扩展可能性。且涂层最有可能发生开裂失效。

Failure Simulation of Thermal Barrier Coatings with a Vertical Crack at the Interface

A finite element model of the nanostructured thermal barrier coating with a vertical crack at the interface between the thermal growing oxide（TGO）and the ceramic layer was established using finite element analysis software ANSYS. The stress distribution map and K1 changing curve at the crack tip in the process of thermal shock test were calculated, The simulation results show that： there exist stress coacentration phenomenon near the crack tip, and the stress intensity factor of crack tip decrease as the time prolong in the cooling process of thermal cycle. At the beginning stages of the cooling process, the variation of the temperature gradient is the biggest, the value of K1 also changes the biggest, the cracks has the greatest possibility of propagation in the initial cooling process. And the cracking failure mode is most likely to occur for the thermal barrier coatings.