The applicability of plate wave techniques for the inspection of adhesive and diffusion bonded joints
The applicability of plate wave techniques for the inspection of adhesive and diffusion bonded joints
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DOI：
10.1007/bf00742584
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发表时间：
1994-12
影响因子：
2.8
通讯作者：
M. Lowe;P. Cawley
中科院分区：
文献类型：
--
作者：
M. Lowe;P. Cawley
本文研究了板波在粘接和扩散焊接接头检测中的作用。这涉及到审查的模态技术，已提出的粘合剂接头的粘合力和凝聚力性能的测量和介绍我们自己的一些研究上的检测和表征的一个不必要的层的脆性α情况下扩散连接钛。可以得出结论，兰姆波，占据整个联合，是可行的原则上，但在这两个应用程序中的限制，由他们的强敏感性的材料特性和厚度的被粘物和他们的相对不敏感的胶层层。另一方面，沿沿着嵌入层传播的嵌入模式对粘附体基本上不敏感，色散曲线显示出对层的性质以及层与粘附体之间的边界条件的灵敏度的重大改进。缺点是，它们的开发在实践中受到限制，因为很难激发和检测它们。真正的模式提供了良好的潜力，但需要访问关节的两端。在试图激发泄漏模式，反射系数的最小值，通常用于测量兰姆波的色散曲线在浸没耦合板，不对应的色散曲线，因为粘附体的声阻抗太大。因此，尽管最小值的测量提供了良好的检查潜力，但这是一种响应技术，不能直接与板模式相关联。在所研究的两个实施例中，界面波都不可能存在于胶层层和被粘物之间的单个界面处。然而，一般来说，这样的模式对于检查可能是相当有吸引力的，只要它们的波长比层厚度小得多，因为它们对界面区域敏感，但对层的厚度不敏感，并且它们测量起来相对简单。
The role of plate waves in the inspection of adhesive and diffusion bonded joints is examined. This involves a review of the modal techniques which have been proposed for the measurement of the adhesion and cohesion properties of adhesive joints and the presentation of some of our own studies on the detection and characterization of an unwanted layer of brittle alpha case in diffusion bonded titanium. It is concluded that Lamb waves, which occupy the whole joint, are viable in principle but are limited in both applications by their strong sensitivity to the material properties and the thicknesses of the adherends and their relative insensitivity to those of the bondline layer. On the other hand, embedded modes, which propagate along an embedded layer, are largely insensitive to the adherends, the dispersion curves showing a major improvement in sensitivity to the properties of the layer and to the boundary conditions between the layer and the adherends. The drawback is that their exploitation is limited in practice because it is difficult to excite and detect them. True modes offer good potential but require access to the ends of the joints. In attempting to excite leaky modes, minima of the reflection coefficient, commonly used to measure Lamb wave dispersion curves in immersion coupled plates, do not correspond to the dispersion curves because the acoustic impedance of the adherends is too large. Therefore, although measurement of the minima offers good potential for inspection, this is a response technique and cannot be associated directly with the plate modes. In neither of the examples studied could an interface wave exist at a single interface between the bondline layer and an adherend. However, in general such modes could be rather attractive for inspection, provided that their wavelengths are much smaller than the layer thickness, because they are sensitive to the interface region but not to the thicknesses of the layers, and they are relatively simple to measure.