承压界面接触特性超声检测

摘要

The non-perfection of contacting interfaces causes the non-trivial features including the contact acoustic nonlinearity （CAN） for ultrasound propagating through the interface. A simple model for one- dimensional longitudinal wave transmission through non-perfect interfaces is proposed, and the transmission coefficient is used to show the interface stiffness. Ultrasonic transmission experiments are carried out to investigate the contact state of the interface under different pressures, and the power-law relationship between the pressure and the stiffness coefficients is established by best fitting the measured ultrasound data. Results show that it is feasible to characterize the pressure-applied interfaces by using the transmission coefficients of the first and second order harmonics in transmitted ultrasonic waves.%针对由于接触界面的非完好性，使得超声波在接触界面处传播呈现非线性效应问题，建立了一维纵波在承压界面传播的简化模型，利用界面处超声波透射系数表征界面刚度．在不同压力下，进行界面超声检测试验，归纳界面刚度系数与压力的幂律系数．结果表明，可利用超声波在接触界面的刚度系数和非线性系数等特征参数进行界面接触状态的评价．