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提出用低频超声类兰姆波定征方法来估计超薄双层胶结复合结构各层的纵波声速、横波声速、厚度和密度等参数 .采用超声耦合剂耦合方式 ,结合超声漏类兰姆波频域分析方法获取复合结构类兰姆波色散曲线 ,提出以色散特性为基础的低频超声类兰姆波定征方法和在最小二乘意义下以色散曲线为基础的反向算法对超薄双层胶结复合结构进行参数估计 .进一步分析了影响估计准确性的各种因素 ,研究了低频超声类兰姆波定征方法对超薄双层胶结复合结构各参数的灵敏度及其在误差传递中的意义 .实验结果证实 ,对于铝 /铜双层胶结复合结构 ,该方法能够准确估计厚度小到 2 4 μm的铝层和铜层的声学参数
This paper proposed the method of low frequency ultrasound Lamb wave to estimate the parameters such as longitudinal wave velocity, shear wave velocity, thickness and density of ultrathin double-layer cemented composite structures.Using ultrasonic coupler coupling method, Domain analysis method was used to obtain the Lambertian dispersion curve of composite structure. The Lambert wave characterization method based on the dispersion characteristic was proposed and the inverse algorithm based on the dispersion curve in the least squares sense Cemented composite structure.Further analysis of the various factors that affect the accuracy of the estimation, the sensitivity of the low frequency ultrasonic Lambert wave characterization method to the parameters of ultra-thin double-layer cemented composite structure and its significance in error transfer The experimental results confirm that this method can accurately estimate the acoustic parameters of aluminum and copper layers as small as 24 μm in thickness for aluminum / copper double-layer cemented composite structures