Nonlinear Lamb wave-mixing technique for micro-crack detection in plates

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• 作者：Jiao Jingpin ; Meng Xiangji ; He Cunfu ; Wu Bin
• 关键词：Micro-crack ; Nonlinear ultrasonic ; Lamb wave mixing ; Sidebands
• 刊名：NDT & E International
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：85
• 期：Complete
• 页码：63-71
• 全文大小：1711 K
• 卷排序：85

文摘

In engineering practice, failures due to fatigue cracks in metallic structures have always been difficult to predict. In our study, nonlinear Lamb wave-mixing was applied in the detection of micro-cracks in plates. The analysis of the nonlinear interaction of these waves with cracks of various lengths and widths was performed using finite-element simulations. The simulation results showed that the sideband at the sum frequency provide a sensitive means for micro-crack detection. Moreover, the sideband amplitudes show a monotonic increase with micro-crack length, but a decrease with micro-crack width. Experiments using Lamb wave-mixing were conducted on plates with fatigue cracks. The experimental results show that a proposed acoustic nonlinearity parameter related to the sideband at the sum frequency is sensitive to micro-cracks in plate, and is well correlated with the damage degree.