Bending of biomimetic scale covered beams under discrete non-periodic engagement
Bending of biomimetic scale covered beams under discrete non-periodic engagement
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DOI：
10.1016/j.ijsolstr.2019.01.021
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发表时间：
2019-07-01
影响因子：
3.6
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
用坚硬的仿生鳞片覆盖弹性基底可通过鳞片接合显着改变弯曲行为。这种啮合是小偏转范围内非线性的主要来源。随着变形的进行，最初的线性弯曲响应让位于逐渐硬化，然后是几何决定的“锁定”配置。然而，迄今为止，即使在鳞片接触之后，仍使用定期参与的假设对该系统进行了研究。仅在最理想的载荷条件下或者尺度极其密集（类似于尺度上的连续统假设）时，这才是正确的。然而，对于规模更加离散并且负载可以改变参与周期的实际系统来说，情况并非如此。我们首次在小偏转和旋转状态下解决这个非线性问题。我们的组合建模和数值分析表明，松弛周期性更好地代表了一般载荷条件下离散尺度啮合的几何形状和梁的力学，并使我们能够重新审视非线性行为。我们报告了在预测参与后秤的行为方面与周期性模型的预测存在显着差异。这些包括鳞片角位移的差异、沿长度的法向力大小、弯矩曲率关系以及锁定行为的独特性质。因此，非周期性是这个问题的一个重要但尚未探索的特征，它带来了以前的研究中所没有的见解。这为开发用于设计和优化这些拓扑杠杆实体的结构-性能-架构框架开辟了道路。 (C) 2019 年由爱思唯尔有限公司出版。
Covering elastic substrates with stiff biomimetic scales significantly alters the bending behavior via scales engagement. This engagement is the dominant source of nonlinearity in small deflection regime. As deformation proceeds, an initially linear bending response gives way to progressive stiffening and thereafter a geometrically dictated 'locked' configuration. However, investigation of this system has been carried out until date using assumption of periodic engagement even after scales contact. This is true only under the most ideal loading conditions or if the scales are extremely dense akin to a continuum assumption on the scales. However, this is not true for a practical system where scales are more discrete and where loading can alter periodicity of engagement. We address this nonlinear problem for the first time in small deflection and rotation regime. Our combined modeling and numerical analysis show that relaxing periodicity better represents the geometry of discrete scales engagement and mechanics of the beam under general loading conditions and allows us to revisit the nonlinear behavior. We report significant differences from predictions of periodic models in terms of predicting the behavior of scales after engagement. These include the difference in the angular displacement of scales, normal force magnitudes along the length, moment curvature relationship as well as a distinct nature of the locking behavior. Therefore, non-periodicity is an important yet unexplored feature of this problem, which leads to insights, absent in previous investigations. This opens way for developing the structure-property-architecture framework for design and optimization of these topologically leveraged solids. (C) 2019 Published by Elsevier Ltd.