This study aims to develop a shear horizontal guided wave based technique to evaluate the interfacial adhesion of aluminium-epoxy-aluminium tri-layer in a lap shear joint. A 3-D Multi-physics finite element model was developed to investigate the physics of the interaction of SH modes with a tri-layer structure. By employing the boundary stiffness approach, different cases of interfacial adhesion-ranging from perfect bond, intermediate and weak bond, were simulated. Frequency-wavenumber analysis reveals that at the bond overlap region, the incident SH₀ wave mode-converts to fundamental (SH₀-like) and first-order(SH₁-like) modes. The dispersion characteristics of first-order mode (SH₁-like) was found to be dependent on the adhesion level, and this influences the time responses collected on a receiver plate in guided wave through-transmission configuration. Experiments were carried out on aluminium-epoxy-aluminium lap shear joints using PPM-EMAT transducers. The analysis shows that this technique can detect and quantify different levels of adhesion, rather than merely classifying as good or bad bonds.

这项研究旨在开发一种基于水平剪切波的技术，以评估搭接剪切接头中铝-环氧-铝三层的界面粘附性。建立了3-D多物理场有限元模型，以研究SH模式与三层结构相互作用的物理过程。通过使用边界刚度方法，模拟了界面粘结的不同情况，包括完美粘结，中间粘结和弱粘结。频率波数分析表明，在键的重叠区域，入射的SH ₀波模式转换为基本（SH ₀类）模式和一阶（SH ₁类）模式。一阶模式（SH ₁（类似）被发现取决于粘附水平，并且这影响了在导波直通透射构造中在接收板上收集的时间响应。实验是使用PPM-EMAT传感器在铝-环氧-铝搭接剪切接头上进行的。分析表明，该技术可以检测和量化不同程度的粘附力，而不仅仅是将其分为好坏两类。