一种定征层状平面结构界面粘接强度的兰姆波方法

置于层状平面结构表面的斜劈超声换能器被用于激发和接收多模兰姆波。文章首先分析了采用多模兰姆波的幅频特性定征界面粘接强度的可行性。基于Ritec-SNAP 超声测量系统,建立了采用兰姆波方法定征层状结构界面粘接强度的实验系统。对于给定的层状平面结构,将粘接层的固化过程用于模拟粘接层界面强度的变化过程。对于不同的粘接层固化时间,实验测得的多模兰姆波幅频曲线明显不同。借助于声——超声技术中的应力波因子,给出了兰姆波应力波因子的定义。实验结果显示,兰姆波应力波因子与间接表示界面粘接强度的固化时间之间存在确定的单调对应关系,表明将多模兰姆波的应力波因子用于定征层状平面结构的界面粘接强度是可行的。

Characterization of Interface Strength of Adhesive Joints of Layered Planar Structures Using a Lamb Wave Approach

Wedge transducers located on the surfaces of layered planar structures are used to generate and detect the multimode Lamb waves. The feasibility of using amplitude-frequency relationships of the multimode Lamb waves to characterize the interface strength of adhesive joints of layered planar structures has been analyzed. Based on the Ritec-SNAP ultrasonic measurement system, the experimental setup for characterizing the interface strength of adhesive joints using a Lamb wave approach has been established. For a given layered planar structure,we use the solidifying process of the adhesive layer to simulate the change process of interface strength of the adhesive joint. For the different solidifying time of the adhesive layer, the measured amplitude -frequency relationships of the multimode Lamb waves are quite different. The Stress Wave Factor (SWF) in acousto-ultrasonic technique is used for reference, and the definition of the SWF of Lamb waves is given. The experimental results show that there is a monotonie relationship between the SWF of Lamb waves and the solidifying time of the adhesive layer, and that the SWF values are quite different for the different solidifying time. It can be concluded that the SWF of the multimode Lamb waves can be used to characterize the interface strength of adhesive joints of layered planar structures.