NUMERICAL ANALYSIS OF THE INCREMENTAL BLIND HOLE DRILLING- METHOD FOR THE STUDY OF RESIDUAL STRESS IN MULTI-LAYER MATERIALS
Advanced multi-layered ceramic coatings applied on metallic substrates are being used increasingly as protective coatings for engine metal components to improve performance at high temperature, e.g. thermal barrier coatings (TBCs) for use in gas turbine components and diesel engines.It is well known that the residual stresses due to the mismatch between metallic bond coat and ceramic top coat as well as the stresses due to the oxidation of the bond coat generate debond- ing of the TBC, leading to a collapse of all thermal barrier system. The incremental hole-drilling strain-gauge method for measuring residual strain in elastic multilayer materials was studied. Theoretical analyses were developed to convert the residual strain measured to stress. The techniques used allow the main stresses to be resolved on planes that are normal to a deep hole. In order to link the surface strain to the residual stress, calibration coefficients were computed with the finite element method The result is that the coefficients depends on the substrate and the type of coating, the strain gauge used and the size of the step drilled. The method proposed enables the residual stress gradient of a thick section of multilayer material to be calculated.
Xu Yingqiang Li Jianfeng Yuan Yuan Wang Zhenlong Lv Guozhi
国际会议
第九届工程结构完整性国际会议(The Ninth International Conference on Engineering Structural Integrity Assessment)
北京
英文
2007-10-15（万方平台首次上网日期，不代表论文的发表时间）