Dynamics of drop impact on soft surfaces has drawn a lot of attention for its applications and is motivated by natural examples like raindrop impact on a leaf. Previous studies have focused on categorizing the bending motion observed, using cantilever beam theory, but the complex dynamic response shown by a leaf involving other degrees of motions like torsion about the petiole, remains yet to be understood. In this study, we demonstrated that the complex response of a superhydrophobic Katsura leaf upon raindrop impact can be decomposed into simple single degree-of-freedom linear modes of bending and torsion, modeled as damped harmonic oscillators. Our theoretical estimates were in good agreement with experimental measurements of the frequency and maximum amplitude of bending and torsional modes. We also illustrated the energy transfer from the raindrop to these modes as a function of the impact location, which may shed light on the design of potential raindrop energy harvesting ...

中文翻译：

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雨滴撞击时弯曲，扭曲和拍打叶片。

水滴在柔软表面上的撞击动力学已引起了广泛的关注，并受到雨滴撞击树叶等自然现象的启发。先前的研究集中于使用悬臂梁理论对观察到的弯曲运动进行分类，但是由叶片显示的涉及其他运动程度（例如围绕叶柄的扭转）的复杂动态响应仍有待了解。在这项研究中，我们证明了超疏水Katsura叶片在雨滴撞击后的复杂响应可以分解为简单的弯曲和扭转的单自由度线性模式，其模型为阻尼谐波振荡器。我们的理论估计与弯曲和扭转模式的频率以及最大振幅的实验测量值非常吻合。