纤维-金属层板粘接质量的非线性超声评价研究

传统超声检测利用超声波传播中遇到缺陷时波的反射、散射等特征进行缺陷检测和评价，实际上表征的是缺陷和周围介质的声阻抗差别。当超声波在材料中传播时，位错等微小缺陷会与其发生非线性相互作用，非线性超声检测就是利用这些非线性响应信号进行材料性能的评估和微小缺陷的检测，本质上反映的是微小缺陷对材料非线性的影响。文中从非线性超声理论出发，提出运用2阶和3阶非线性系数进行纤维-金属粘接层的评价，实验结果表明非线性系数可以表征粘接缺陷。

Nonlinear ultrasonic testing of adhesive interfaces in FML

The traditional ultrasonic nondestructive testing uses the characteristics such as wave reflection,scattering and so on occurred when meeting the defects during ultrasonic propagation,actually which characterize the acoustic impedance different between the defects and the environmental media.During the ultrasonic propagation in the material,the dislocation and micro defects can produce the nonlinear interaction with the ultrasonic wave,the nonlinear ultrasonic testing uses these nonlinear response signals to carry on the material performance evaluation and the micro defects testing, essentially reflects the nonlinear effect of the micro defects on the material.On account use of the nonlinear acoustic theory,this paper put forward using the second-order and third-order nonlinear coefficient to evaluate the bonding layers of fibre metal laminates.The results indicated that the nonlinear coefficients can be used to attribute the bonding defects.