In this paper, we clarify the nonlinear interaction between tuned Rayleigh waves and evolving fatigue damage and achieve evolving fatigue damage detection. Firstly, the impact of laser parameters on Rayleigh waves is investigated to generate stronger Rayleigh waves. Secondly, the multi-component nonlinear modulation mechanism of Rayleigh waves is analyzed using the nonlinear model considering contact and friction. The simulation results indicate that during the plastic deformation stage, waveform distortion is minimal. As microcracks form, the longitudinal wave component becomes dominant in Rayleigh wave nonlinearity due to contact and friction behaviors between microcrack faces, resulting in waveform distortion, harmonic generation, and increased acoustic nonlinearity parameters. However, the shear wave component only exhibits high-frequency filterability without nonlinearity. As macrocracks develop, both longitudinal and shear wave component amplitudes decrease significantly. Finally, an experimental validation is carried out. The experimental results validate that the acoustic nonlinearity parameters first stabilize and then increase significantly from the pristine state to the microcrack propagation, and the indicator can be utilized for fatigue damage detection. The research can provide guidance for nonlinear laser-generated Rayleigh wave detection of fatigue damage.

中文翻译：

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基于调谐激光产生瑞利波的多分量非线性调制机制的演化疲劳损伤检测

在本文中，我们阐明了调谐瑞利波与演化疲劳损伤之间的非线性相互作用，并实现了演化疲劳损伤检测。首先，研究激光参数对瑞利波的影响，以产生更强的瑞利波。其次，利用考虑接触和摩擦的非线性模型分析了瑞利波的多分量非线性调制机制。仿真结果表明，在塑性变形阶段，波形畸变最小。随着微裂纹的形成，由于微裂纹面之间的接触和摩擦行为，纵波分量在瑞利波非线性中占主导地位，导致波形畸变、谐波产生和声学非线性参数增加。然而，剪切波分量仅表现出高频滤波能力，而没有非线性。随着宏观裂纹的发展，纵波和横波分量的振幅均显着减小。最后进行实验验证。实验结果验证了声学非线性参数从原始状态到微裂纹扩展先稳定后显着增加，该指标可用于疲劳损伤检测。该研究可为非线性激光瑞利波疲劳损伤检测提供指导。