A compliant guiding mechanism utilizing orthogonally oriented flexures with enhanced stiffness in degrees-of-constraint
A compliant guiding mechanism utilizing orthogonally oriented flexures with enhanced stiffness in degrees-of-constraint
复制标题
一种柔顺导向机构，利用正交定向的挠曲件，在约束度方面具有增强的刚度
DOI：
10.1016/j.mechmachtheory.2021.104555
复制
发表时间：
2021-09-23
影响因子：
5.2
通讯作者：
Wei, Yutai
中科院分区：
文献类型：
--
作者：
Li, Ruiqi;Yang, Zhijun;Wei, Yutai
大行程通常通过沿自由度降低刚度来实现，这通常导致沿约束度的刚度减小。高刚度比对于减小由诸如偏心力和载荷重力等扰动引起的挠度至关重要。此外，由于大挠度引起的大应力，这些机构的疲劳寿命将缩短。提出了一种利用正交柔性体提高导向机构沿约束度沿着刚度和减小应力集中的新导向机构。利用能量法建立了考虑非线性变形的导向机构静力学模型，并在此基础上对导向机构进行了拓扑和尺寸同时优化。与相同优化目标和约束条件下的传统设计相比，优化后的结构刚度沿着约束度有了明显提高，有限元分析结果也验证了优化设计的准确性。实验结果表明，该机构的刚度比Kaz/Kx比传统机构提高了3.54倍。
The large stroke is usually realized by lowering stiffness along the degrees of freedom, which usually leads to a decrease of stiffness along the degrees of constraint. A high stiffness ratio is crucial for reducing the deflections induced by disturbances such as eccentric force and the gravity of the load. Besides, the fatigue life of these mechanisms will be shortened due to the large stress caused by the large deflection. This paper proposed a new guiding mechanism using orthogonally oriented flexures to improve the stiffness along the degrees of constraint and reduce stress concentration. The energy method is utilized to obtain the kinetostatic model of the guiding mechanism by taking the nonlinear deflection into account, based on which the mechanism is optimized by simultaneously considering the topology and size. As compared to the performance of traditional design obtained through the same optimization objective and constraints, the optimal design effectively improves the stiffness along the degrees of constraint, whose accuracy is also validated by the finite element analysis results. Experimental results show that the proposed mechanism increases the stiffness ratio Kaz/Kx by 3.54 times compared to the traditional mechanism.