热障涂层热应力影响因素的正交有限元分析

利用有限元分析方法,采用Walker粘塑性材料本构模型计算了喷涂于圆管型试件上的热障涂层在室温和高温环境下的热应力.使用试验中常用的正交设计分析方法,分析了热障涂层不同的结构和喷涂工艺中的4种因素在取不同的水平条件时对热障涂层热应力的影响.分析结果表明:对于所考察的危险点,4种因素对热障涂层中热应力的产生都有显著影响,其中以氧化层的厚度对其影响最为严重;4种因素随其各自水平的变化对涂层内部应力变化的影响规律不同.

Finite element analysis of factors to thermal stress in thermal barrier coatings with orthogonal method

The thermal stresses in room and elevated temperatures were studied in thermal barrier coatings (TBCs) which was coated at the outer surface of pipe specimens, using finite element method (FEM), and the Walker viscoplastic theory was adopted to depicting the stress-strain constitution in the ceramic layer. During the design of FEM analysis computation, the orthogonal design method widely used in experiment study, was used, and the contributions of four factors to the being of thermal stress were achieved. The results show that the four factors have the remarkable effect to thermal stress in TBCs, and the factor of thermally grown oxide is the most important, the stress changing rules of four factors are different in TBCs with the ascending of levels.