热障涂层厚度及其涂敷下材料内部缺陷的红外定量识别

针对热障涂层结构材料红外定量检测存在的不足,提出基于脉冲相位的LM(LevenbergMarquardt)识别算法。针对研究问题,建立了轴对称圆柱坐标下热障涂层结构材料的瞬态导热模型,利用有限体积法计算出检测表面的温度场,经快速傅里叶变换得到检测表面的相位分布,分析待检测参数对检测表面相位差的影响。以相位为识别条件,采用LM反演算法对热障涂层厚度及其涂敷下材料内部缺陷位置大小进行定量识别,并采用数值实验方法验证了基于相位的LM识别方法的有效性。

Quantitative identification of coating thickness and inner defects of the material by infrared testing technology

Aiming at the problems of infrared quantitative detection of thermal barrier coating structures, the LM (Levenberg-Marquardt) recognition algorithm based on pulse phase was put forward. The transient thermalmodel of TBC structures by an axisymmetric cylindrical coordinates was established in view of the research problem. The surface temperature field of the research model was calculated by the finite volume method. And then the phase of the inspection surface was obtained through FFT. The impacts of parameters to be detected on the phase of the inspection surface were analyzed. Based on the phase for the input parameter, quantitative identification method of coating thickness and inner defects of the metal was researched by using LM recognition algorithm. The quantitative identification method based on phase detection was verified by using numerical experiment. The effectiveness of the quantitative identification method was evidenced on the basis of the numerical experiment results.