In this study, the effect of friction on the generation of dry-coupled Lamb waves is experimentally investigated. Recurrence analysis is performed to analyze the complex behavior of friction based dry-coupled Lamb waves. In particular, the effect of the normal force, which is necessary for a stronger dry-coupled Lamb wave generation and the friction, on the transmission of mechanical energy and determinism characteristics of Lamb waves are investigated. The results verify that larger friction coefficient and friction force are crucial for generation and propagation of strong Lamb waves supporting the fact that the main mechanism to transfer mechanical energy using dry-couplant is friction. The sensitivity of Lamb waves to the friction coefficient, highlights the importance of designing specific pads with respect to condition of the surface. Besides, the results show that the normal force and friction coefficient can change the determinism characteristics behavior of multimode Lamb waves. Furthermore, it is shown that the determinism value is sensitive to the friction coefficient and normal force. A similar trend is observed in the determinism values and friction coefficient. In general, a smaller friction coefficient indicates smaller determinism value. Additionally, it is shown that a normal load can change the behavior of a system, as observed from recurrence plots, owing to changes in the Lamb waves trajectories in the phase-space domain. In addition, it is shown that recurrence plots enable the detection of mode transitions in multimode Lamb waves. Recurrence analysis is a complementary tool to frequency domain methods for accurate analysis of multimode Lamb waves behavior.

在这项研究中，摩擦对干耦合兰姆波产生的影响进行了实验研究。执行递归分析以分析基于摩擦的干耦合兰姆波的复杂行为。特别是，研究了产生更强干耦合兰姆波和摩擦所必需的法向力对机械能传递和兰姆波确定性特征的影响。结果证实，较大的摩擦系数和摩擦力对于强兰姆波的产生和传播至关重要，这支持了使用干耦合剂传递机械能的主要机制是摩擦这一事实。兰姆波对摩擦系数的敏感性突出了根据表面状况设计特定垫的重要性。除了，结果表明，法向力和摩擦系数可以改变多模兰姆波的确定性特征行为。此外，它表明确定性值对摩擦系数和法向力敏感。在确定性值和摩擦系数中观察到类似的趋势。一般来说，较小的摩擦系数表示较小的确定性值。此外，从递归图中观察到，由于相空间域中兰姆波轨迹的变化，正常负载可以改变系统的行为。此外，还表明递归图能够检测多模兰姆波中的模式转换。递归分析是频域方法的补充工具，用于准确分析多模兰姆波行为。