Coulomb friction in twisting of biomimetic scale-covered substrate
Coulomb friction in twisting of biomimetic scale-covered substrate
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DOI：
10.1088/1748-3190/ab9f80
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发表时间：
2020-01
影响因子：
3.4
通讯作者：
Hossein Ebrahimi;Hessein Ali;Hossein Ebrahimi
中科院分区：
文献类型：
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作者：
Hossein Ebrahimi;Hessein Ali;Hossein Ebrahimi
仿生鳞片覆盖基板通过鳞片方向、间距以及在各种变形模式下接触的界面属性提供几何可裁剪性。目前还没有研究摩擦对仿生鳞片覆盖梁扭转变形的影响。在这项工作中，我们通过建立有限元模拟验证的分析模型来研究仿生鳞片覆盖结构中的摩擦效应。在该模型中，我们将刚性鳞片表面与衬底之间的干(库仑)摩擦视为线弹性矩形梁。结果表明，摩擦力对系统具有双重贡献，一是由于机构由纯运动学行为转变为界面行为而使闭锁机构提前，二是由于啮合力的急剧增加而使扭转响应变硬。我们还发现，通过将工程尺度表面潜在的摩擦系数增加到一个临界系数，系统可以达到瞬时啮合后锁定。开发的模型概述了几何形状、变形、摩擦力和应变能之间的解析关系，以设计适用于广泛应用的仿生尺度覆盖的超材料。
Biomimetic scale-covered substrates provide geometric tailorability via scale orientation, spacing and also interfacial properties of contact in various deformation modes. No work has investigated the effect of friction in twisting deformation of biomimetic scale-covered beams. In this work, we investigate the frictional effects in the biomimetic scale-covered structure by developing an analytical model verified by finite element simulations. In this model, we consider dry (Coulomb) friction between rigid scales surfaces, and the substrate as the linear elastic rectangular beam. The obtained results show that the friction has a dual contribution on the system by advancing the locking mechanism due to change of mechanism from purely kinematic to interfacial behavior, and stiffening the twist response due to sharp increase in the engagement forces. We also discovered, by increasing the coefficient of friction potentially using engineering scale surfaces to a critical coefficient, the system could reach to instantaneous post-engagement locking. The developed model outlines analytical relationships between geometry, deformation, frictional force and strain energy, to design biomimetic scale-covered metamaterials for a wide range of applications.