建立了铝薄板微小缺陷的非线性Lamb波检测系统，利用该系统对未去应力和去应力后的两组铝合金试块进行检测，得到残余应力对Lamb波非线性效应的影响趋势。试验结果表明，当试样疲劳程度较小时，残余应力的存在会增大试样的超声非线性效应；当试样疲劳程度达到总寿命的62.5%后，试样内部产生微裂纹，非线性效应主要取决于微裂纹的大小，而残余应力对非线性的影响较小。

A nonlinear Lamb wave detection system for detecting microdefects of aluminum sheets was established. The system was used to detect the two sets of aluminum alloy test blocks after unstressed and de-stressed, and the influence of residual stress on the nonlinear effect of Lamb waves was obtained. The experimental results show that when the fatigue degree of the sample is small, the existence of residual stress will increase the ultrasonic nonlinear effect of the sample,whereas when the fatigue degree of the sample reaches 62.5% of the total life, microcracks are generated inside the sample. The nonlinear effect mainly depends on the size of the microcracks, and the residual stress has little effect on the nonlinear effect.