Structural health monitoring using nonlinear guided waves have found to be of great importance. The detection of micro/fatigue cracks in the early stage is essential to avoid catastrophic failures. This paper presents a defect localization technique using nonlinear interaction primary Lamb wave modes. The nonlinearity employed here is due to clapping behaviour of crack surfaces. Two counter-propagating Lamb waves with dissimilar frequencies are allowed to mix at various locations. The results show that the sensitivity of nonlinearity due to crack wave interaction increases when Lamb wave mixing occurs at the fault zone. To study the extent of nonlinearity on damage size, studies were also conducted on plates with different crack parameters. The study reveals that the nonlinear Lamb wave mixing technique can be used effectively to detect and localize micro-crack in plate-like structures.

中文翻译：

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使用非线性兰姆波混合技术的缺陷定位

已经发现使用非线性导波的结构健康监测非常重要。在早期阶段检测微/疲劳裂纹对于避免灾难性故障至关重要。本文提出了一种使用非线性相互作用初级兰姆波模式的缺陷定位技术。这里采用的非线性是由于裂纹表面的拍击行为。允许具有不同频率的两个反向传播的兰姆波在不同位置混合。结果表明，当断裂带发生兰姆波混合时，裂纹波相互作用引起的非线性敏感性增加。为了研究损伤尺寸的非线性程度，还对具有不同裂纹参数的板进行了研究。