摘要
采用热弹塑性有限元方法,对热障涂层多次热循环降温过程中由于热梯度和材料参数不匹配而产生的残余应力进行了数值模拟,分析了平面和曲面的界面形貌对界面残余应力的影响。结果表明,在相同材料参数情况下,陶瓷层与粘接层的界面形状对残余应力及结构稳定状态有显著的影响,凹凸不平的界面将会使界面残余应力发生突变,不利于增强界面结合强度和涂层结构的热稳定性。该结果对分析涂层寿命及失效机制有指导意义。
The residual stress accumulation during thermal cycling of thermal barrier coatings was simulated by thermal elastic-plastic finite element method when considered of thermal grads and thermal expansion misfit in this paper. And the influences of the interracial topography on residual stress were analyzed. The results show that the residual stress and stabilization process are affected remarkably by interracial topography between top coat and bond coat. Accidented interface will cause the sudden change of the interfacial residual stress which is bad to interface bonding intensity and stabilization. The results are useful information for studying af the life and final spallation afTBC system.
出处
《机械设计与制造》
北大核心
2007年第6期77-79,共3页
Machinery Design & Manufacture
基金
国家自然科学基金项目(106721340)
关键词
热障涂层
热循环
残余应力
有限元方法
Thermal barrier coatings
Thermal cycling
Residual stress
Finite element method
