Kissing bonds in adhesive joints: a holistic approach for nonlinear ultrasonic detection, joint mechanics and surface chemistry

接触粘结是粘合剂粘结缺陷，其中粘合剂和基材通过弱粘结或薄层接触或联接。它们被认为是由制造过程中表面的污染或各种形式的环境侵蚀引起的。当粘合剂用于安全关键应用时，目前的方法是进行非常仔细的过程控制。尽管如此，粘合接头的过早失效仍然会发生，而吻接是最可能的原因。除此之外，阻碍更广泛地使用粘合剂结合的限制因素之一是缺乏能够检测对接结合的定量非破坏性测试程序。然而，尽管有这种需要，接吻键的物理性质和它们的失效机制是未知的。这种知识的缺乏是进步的基本障碍，并抑制了适当的无损检测程序的设计。本计画旨在探讨胶接接头中的吻接现象，并矫正目前缺乏了解的现象。该项目将采取全面的方法，并获得1）对接吻键的物理性质的详细了解; 2）对接吻键如何导致机械故障的理解; 3）使用当前最先进的方法（高频超声）和使用非线性超声波（这是一种令人兴奋的新兴技术）对其可检测性进行调查。

A kissing bond is an adhesive bonding defect in which the adhesive and the substrate are in contact or coupled though a weak bond or thin layer. They are thought to arise from either contamination of the surfaces during manufacture or various forms of environmental attack. When adhesives are used for safety critical applications the current approach is to undertake extremely careful process control. None-the-less premature failure of adhesive joints still occurs and kissing bonds are the most likely cause. In addition to this, one of the limiting factors preventing the more widespread use of adhesive bonding is the lack of quantitative non-destructive testing procedures capable of detecting kissing bonds. However, despite this need, the physical nature of the kissing bonds and their failure mechanics are unknown. This lack of knowledge acts as a fundamental barrier to progress and inhibits the design of appropriate NDT procedures. This project aims to investigate the phenomena of kissing bonds in adhesive joints and redress this lack of current understanding. The project will take a holistic approach and obtain 1) a detailed understanding of the physical nature of kissing bonds; 2) an understanding of how kissing bonds lead to a mechanical failure and; 3) undertake an nvestigation into their detectablity using both current state-of-the-art methods (high frequency ultrasonics) and using nonlinear ltrasonics which is an exciting emerging technology.