Building Block-Based Spatial Topology Synthesis Method for Large-Stroke Flexure Hinges

Abstract

Large-stroke flexure mechanisms inherently lose stiffness in supporting directions when deflected. A systematic approach to synthesize such hinges is currently lacking. In this paper, a new building block-based spatial topology synthesis method is presented for optimizing large-stroke flexure hinges. This method consists of a layout variation strategy based on a building block approach combined with a shape optimization to obtain the optimal design tuned for a specific application. A derivative-free shape optimization method is adapted to include multiple system boundaries and constraints to optimize high complexity flexure mechanisms in a broad solution space. To obtain the optimal layout, three predefined three-dimensional (3D) “building blocks” are proposed, which are consecutively combined to find the best layout with respect to specific design criteria. More specifically, this new method is used to optimize a flexure hinge aimed at maximizing the frequency of the first unwanted vibration mode. The optimized topology shows an increase in frequency of a factor ten with respect to the customary three flexure cross hinge (TFCH), which represents a huge improvement in performance. The numerically predicted natural frequencies and mode shapes have been verified experimentally.

Design and Analysis of Flexible Hinge Used for Unfolding Spacecraft Solar Panels

“…The allowable shear stress [τ] = 17 MPa. Based on the size of the hinges given in Delimont et al (2015), Dewalque et al (2016), and Naves et al (2017), the parameter values of the hinge are set. The radii of the inner cylinder and outer ring are r = 6 mm, R = 30 mm.…”

Optimal Design and Tracking Control of a Superelastic Flexure Hinge Based 3-PRR Compliant Parallel Manipulator

“…With the development of modern precision engineering, CPMs with centimeter motion range are highly demanded in biomedical sciences and optical engineering, such as, scanning probe microscopy, lithography, and cell micromanipulation [6], [7]. A promising way to enlarge the motion range of notched flexure hinge based CPMs is to improve the deformability of the material which used to fabricate the flexure hinges.…”

Design of flexure revolute joint based on double compliant curved beam

“…There are many methods, which have been found to design compliant mechanism: freedom and constraint topology (FACT), 15,16 topology optimization, 17 pseudo-rigid-body method, 18 and building block approach. 19,20 FACT is used to synthesize concepts for the multi-degrees of freedom and parallel precision flexure systems. Topology optimization involves the selective reduction of a network of finite elements to ascertain the ideal number connectivity of elements.…”

“…19 A new building block-based spatial topology synthesis method is presented for optimizing large-stroke flexure hinges. 20 The compliance and stiffness ellipsoids can fit the compliance of a structure in different directions with the need of the structure. The structure, which is designed by using constant dimension, is easier to manufacture than the structure that is got by topological method and FACT.…”