In this study, the integrated detection method for open and closed surface fatigue cracks is investigated. Firstly, the finite element simulation models are established to investigate the interaction between scanning laser source-induced Rayleigh waves and open and closed surface fatigue cracks, and the laser ultrasonic detection experiments are conducted for fatigue specimens containing fatigue cracks in different states. The simulation and experimental results indicate that the variation patterns in the peak-to-peak values of Rayleigh waves with horizontal scanning positions for open and closed cracks exhibit both similarities and differences. Subsequently, an integrated detection method based on self-referenced peak-to-peak features is proposed, which utilizes the similarities and differences to detect and distinguish open and closed cracks, respectively. Furthermore, this proposed method is experimentally validated, indicating that it can achieve accurate integrated imaging of open and closed cracks that have a high degree of agreement with the SEM images of the cracks. Additionally, the proposed method achieves a detection error of 2 % for the vertical lengths of the fatigue cracks. This study can provide guidance for integrated real-time detection of open and closed surface fatigue cracks of mechanical components in service.

中文翻译：

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利用具有自参考峰峰值特征的扫描激光源诱导瑞利波场，对开放和封闭表面疲劳裂纹进行集成检测


本研究研究了开放和封闭表面疲劳裂纹的集成检测方法。首先，建立有限元仿真模型，研究扫描激光源诱导瑞利波与开闭表面疲劳裂纹的相互作用，并对含有不同状态疲劳裂纹的疲劳试件进行激光超声探测实验;仿真和实验结果表明，在水平扫描位置对开裂和闭合裂纹的瑞利波的峰峰值变化模式既有相似之处，也有不同之处。随后，提出了一种基于自引用峰峰值特征的集成探测方法，利用两者的相似性和差异性分别探测和区分开放和封闭的裂纹。此外，该方法经过实验验证，表明它可以实现与裂纹的 SEM 图像高度吻合的开放和闭合裂纹的准确集成成像。此外，所提出的方法对疲劳裂纹的垂直长度的检测误差为 2%。该研究可为在役机械部件开闭表面疲劳裂纹的集成实时检测提供指导。