板状构件粘结强度的非线性超声导波检测

相较于铆接、螺接、焊接等连接方式，板状粘结构件具有质量轻、应力分布均匀等特点，广泛运用于航空航天、车辆制造等工业领域。板状粘结构件在服役过程中出现的粘结强度退化、弱粘结等会影响其服役可靠性及安全性，因此对粘结强度进行检测十分必要。非线性超声导波对材料微观结构特征变化比较敏感，可用于粘结构件的粘结强度检测。采用非线性超声导波对铝合金-环氧树脂-铝合金板状构件进行检测，通过不同的固化工艺制备粘结结构件模拟不同粘结强度，检测结构件中传播的非线性超声导波，计算超声非线性参量，获得超声非线性参量在不同固化工艺下的变化趋势。通过拉伸实验测得粘结强度，进而构建超声非线性参量与粘结强度的关系。实验结果显示，粘结强度越大，超声导波的非线性参量越小。该研究表明，非线性超声导波可有效检测板状构件的粘结强度，为工业检测板状结构粘结强度提供了有效方法。

Nonlinear ultrasonic guided wave measurement of bonding strength of plate components

Plate bonded structures are widely used in aerospace and vehicle manufacturing and other industrial fields due to the characteristics of light weight and uniform stress distribution compared with the connection methods of riveting, screw, welding and others. The bonding strength degradation and weak bonding will affect the reliability and security of bonded components, so it is very important to test them. The nonlinear ultrasonic guided wave is sensitive to the microstructure change of materials and can be used to detect the bonding strength degradation of bonded components. In this paper, the nonlinear ultrasonic guided wave is used to test the aluminum alloy - epoxy resin - aluminum alloy plate bonded components, which are prepared through the different curing processes to simulate different bonding strengths. In the experiments, by detecting the nonlinear ultrasonic guided wave propagating in the components and then calculating the ultrasonic nonlinear parameters, the variation trends of ultrasonic nonlinear parameters under different curing processes are obtained. The corresponding bonding strengths of components are measured by tensile tests, and then the relationships between ultrasonic nonlinear parameters and bond strength are established. The experimental results show that the greater the bonding strength, the smaller the nonlinear parameters of the ultrasonic guided wave. So, the nonlinear ultrasonic guided wave can be effectively used to detect the bonding strength of plate components, providing an effective method for industrial testing of the bonding strength of plate components.