Chen Han, Xu Caibin, Gao Guangjian, Chen Yan, Bai Yunshan, Deng Mingxi
Army Logistics Academy, Chongqing 401331, China.
College of Aerospace Engineering, Chongqing University, Chongqing 400044, China.
Ultrasonics. 2025 Apr;148:107567. doi: 10.1016/j.ultras.2025.107567. Epub 2025 Jan 7.
This study delves into the feasibility of leveraging quasi-static component (QSC) generation during primary Lamb wave propagation to discern subtle alterations in the interfacial properties of a two-layered plate. Unlike the second-harmonic generation of Lamb waves, QSC generation doesn't necessitate precise phase-velocity matching but rather requires an approximate matching of group velocities to ensure the emergence of cumulative growth effects. This unique characteristic empowers the QSC-based nonlinear ultrasonic method to effectively surmount the limitations associated with inherent dispersion and multimode traits of Lamb wave propagation. Modeling the QSC generation reveals that the integrated amplitude of the QSC pulse, derived from the propagation of the primary Lamb wave tone burst, progressively amplifies with increasing propagation distance. Finite element simulations illustrate an overall decline in the efficiency of QSC generation amidst interfacial degradation. Experimental outcomes obtained via a nonlinear ultrasonic measurement-based setup vividly showcase the cumulative growth effect of QSC generation, evident with the propagation distance under approximate group velocity matching. To substantiate the influence of interfacial properties on QSC generation efficiency, varying thermal fatigue durations under cyclic temperature conditions are employed to simulate subtle changes in the two-layered plate's interfacial properties. The relative nonlinear acoustic parameter exhibits a distinctly sensitive and monotonically decreasing behavior with escalating thermal fatigue durations, corroborating the impact of alterations in interfacial properties on QSC generation efficiency. The alignment between experimental findings and numerical analysis predictions suggests that the effect of QSC generation in primary Lamb wave propagation provides a promising means for sensitively assessing the early-stage degradation of interfacial properties in layered plates.
本研究深入探讨了在初级兰姆波传播过程中利用准静态分量（QSC）生成来识别双层板界面特性细微变化的可行性。与兰姆波的二次谐波生成不同，QSC生成不需要精确的相速度匹配，而是需要群速度的近似匹配，以确保累积增长效应的出现。这一独特特性使基于QSC的非线性超声方法能够有效克服与兰姆波传播固有的色散和多模特性相关的局限性。对QSC生成进行建模表明，由初级兰姆波短脉冲传播产生的QSC脉冲的积分幅度随着传播距离的增加而逐渐放大。有限元模拟表明，在界面退化过程中，QSC生成的效率总体下降。通过基于非线性超声测量的设置获得的实验结果生动地展示了QSC生成的累积增长效应，在近似群速度匹配下，随着传播距离而明显可见。为了证实界面特性对QSC生成效率的影响，采用循环温度条件下不同的热疲劳持续时间来模拟双层板界面特性的细微变化。相对非线性声学参数随着热疲劳持续时间的增加呈现出明显敏感且单调下降的行为，证实了界面特性变化对QSC生成效率的影响。实验结果与数值分析预测之间的一致性表明，初级兰姆波传播中QSC生成的效应为灵敏评估层状板界面特性的早期退化提供了一种有前景的方法。
