Design of Compliant Actuation Mechanisms by Evolutionary Structural Optimization Method

doi:10.3901/JME.2021.19.004

Abstract

Abstract: This research proposes a topology optimization design strategy for compliant actuation mechanisms using the evolutionary structural optimization (ESO) method. Because of the discrete nature of design variables (0/1) and heuristic update mechanism, ESO-type methods have been mainly applied for convex optimization problems such as structural stiffness maximization design. Compliant mechanisms design with maximized actuated displacements as the design objective is a typical non-convex problem and ESO methods cannot be applied directly. In this regard, a weighted objective function is proposed by combining actuated displacement and structural stiffness (in terms of compliance). The merits of the newly defined objective function are twofold. First, by gradually (design iterations) damping the stiffness contribution, the design objective dynamically evolves from stiffness to actuation, and thus ESO methods can be applied. Second, a flexible control on actuation and stiffness performances can be achieved by adjusting the weights, which assists in avoiding the appearance of fragile hinges and prevents failure due to stress concentration. By means of a series of benchmark design tests, the proposed evolutionary design strategy has been shown robust and high-efficient in designing compliant actuation mechanisms.

Key words: compliant mechanism, topology optimization, ESO, dynamic evolution, actuation design

CLC Number:

O343

HE Jian, HE Meng, XIA Liang, SHI Tielin. Design of Compliant Actuation Mechanisms by Evolutionary Structural Optimization Method[J]. Journal of Mechanical Engineering, 2021, 57(19): 39-47.

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