金属薄板检测中, 声-超声检测方法可激发多模式的兰姆波, 兰姆波能够评价金属胶接后结构质量, 正确认识兰姆波传播特性与胶接接头强度的关系是有效应用该技术的基础。采用有限元模拟的方法, 对金属板胶接接头中声-超声激励方式建模。将胶接接头内聚强度与兰姆波的传播模式联系起来, 在0.5 MHz和1 MHz两种激发频率下, 随着胶层内聚强度的降低, 得出了对应兰姆波模式在胶接接头处内聚强度的频谱图和相对能量的变化曲线。该法能为实验研究、实际检测提供有效理论依据。

It is a kind of multimode lamb wave that motivates the Acousto-ultrasonic(AU) signals when a thin plate is tested by the AU method. Lame waves can evaluate the quality of the structure of adhesive joints. The relationship between propagation characteristic of lamb and bonding strength of the joints is the effective application of this technology. In this paper, an FEM method is used to simulate the acousto-ultrasonic in the adhesive joints and combines cohesive strength with the propagation characteristic of lame waves in the frequency from 0.5 MHz to 1 MHz. It shows the variation curves of lame wave mode energy as the cohesive strength is lower. This method provides theoretical basis for the experimental studies and the actual testing.