Frictional Damping from Biomimetic Scales
Frictional Damping from Biomimetic Scales
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DOI：
10.1038/s41598-019-50944-0
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发表时间：
2019-10-10
影响因子：
4.6
通讯作者：
Ghosh, Ranajay
中科院分区：
文献类型：
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作者：
Ali, Hessein;Ebrahimi, Hossein;Ghosh, Ranajay
硬鳞装饰在鱼、蛇和许多爬行动物的外部表面。它们提供免受外部穿透攻击的保护，并控制全球变形行为，以帮助在广泛的环境条件下移动、滑行和游泳。在这份报告中，我们研究了仿生鳞片底物的动力学行为，以进一步了解涉及鳞片相互作用、滑动运动学、界面摩擦及其组合的各个方面的非线性的起源。特别地，我们通过解析模型和数值研究，研究了简支缩尺盖梁的振动特性。我们的结果首次表明，即使只假设自由振动的库仑摩擦，仿生尺度梁也表现出粘性阻尼行为。我们预测并量化了阻尼行为相对于曲率的各向异性。我们还发现，与摩擦增加弯曲刚度的静态纯弯曲不同，对于简支梁，动力情况下的固有频率不会出现相应的增加。由于尺度的几何形状、分布和界面属性都可以很容易地定制，我们的研究表明了一种仿生策略来设计具有可定制阻尼行为的特殊合成材料。
Stiff scales adorn the exterior surfaces of fishes, snakes, and many reptiles. They provide protection from external piercing attacks and control over global deformation behavior to aid locomotion, slithering, and swimming across a wide range of environmental condition. In this report, we investigate the dynamic behavior of biomimetic scale substrates for further understanding the origins of the nonlinearity that involve various aspect of scales interaction, sliding kinematics, interfacial friction, and their combination. Particularly, we study the vibrational characteristics through an analytical model and numerical investigations for the case of a simply supported scale covered beam. Our results reveal for the first time that biomimetic scale beams exhibit viscous damping behavior even when only Coulomb friction is postulated for free vibrations. We anticipate and quantify the anisotropy in the damping behavior with respect to curvature. We also find that unlike static pure bending where friction increases bending stiffness, a corresponding increase in natural frequency for the dynamic case does not arise for simply supported beam. Since both scale geometry, distribution and interfacial properties can be easily tailored, our study indicates a biomimetic strategy to design exceptional synthetic materials with tailorable damping behavior.