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提出用低频超声类兰姆波定征方法来估计超薄黏结复合结构各层与黏结层的厚度、密度、纵波声速和横波声速等参数 .采用超声耦合剂耦合方式 ,结合超声泄漏类兰姆波频域分析方法获取黏结复合结构类兰姆波频散曲线 ,提出以频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频散曲线为基础的反向算法对超薄黏结复合结构各层与黏结层进行了参数估计 .还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黏结复合结构中各层参数的灵敏度及其在误差传递中的意义 .实验结果证实 ,对于超薄不锈钢 /黄铜黏结复合结构 ,该方法能够准确估计各层 h<0 .0 5λ复合结构的声学参数
The method of low frequency ultrasonic Lambam wave is used to estimate the parameters such as thickness, density, longitudinal wave velocity and shear wave velocity of each layer and bonding layer of ultrathin bonded composite structure.Using ultrasonic coupling agent coupling method and ultrasonic leakage type Lamb wave The frequency domain analysis method is used to obtain the Lambert wave dispersion curve of the bonded composite structure. The method of Lamb waves’ identification based on the frequency dispersion characteristic and the inverse algorithm based on the dispersion curve in the least square sense The parameters of each layer and bonding layer of the ultrathin bonded composite structure are estimated, and various factors affecting the accuracy of the estimation are also analyzed. The effects of low frequency ultrasonic Lambert method on the parameters of each layer in the ultrathin bonded composite structure Sensitivity and its significance in error transmission.The experimental results show that the method can accurately estimate the acoustic parameters of h <0. 05λ composite structure for ultra-thin stainless steel / brass bonded composite structures