An augmented formulation of distributed compliant mechanism optimization using a level set method

Abstract

Topology optimization has emerged as one of the key approaches to design compliant mechanisms. However, one of the main difficulties is that the resulted compliant mechanisms often have de facto hinges. For this reason, a simple yet efficient formulation for designing hinge-free compliant mechanisms is developed and examined within a level set-based topology optimization framework. First, the conventional objective function is augmented using an output stiffness. Second, the proposed formulation is solved using a level set method for designing some benchmark problems in the literature. It is shown that the proposed augmented objective function can prevent the de facto hinges in the obtained compliant mechanisms. Finally, some concluding remarks and future work are put forward.

On the design of a novel fully compliant spherical four-bar mechanism

“…If b min exists, the maximum deflection of compliant segment 1-2 (Db max ) cannot exceed 180°2 b min . The relationship between g and u can be determined from equation (10) cos a 1 cos a 4 + sin a 1 sin a 4 cos u À cos a 2 cos a 3 = sin a 2 sin a 3 cos g ð10Þ…”

“…9 In the literature, planar compliant mechanisms have been extensively studied. [10][11][12] However, there are limited studies available on spatial compliant mechanisms. 13 A special case of the spherical four-bar mechanism, the compliant Cardan universal joint, was studied by the authors, and it was ensured that compliant segments are majorly exposed to normal stresses due to bending.…”

Topology optimization of a 6-DOF spatial compliant mechanism based on Stewart propotype platform

“…There is no need to pre-determine the number of links or the location of the flexural joints in the device [14]. In the past decades, many different techniques, such as the homogenization method [15], solid isotropic material with penalization (SIMP) method [16][17][18], level set method [19,20], evolutionary structural optimization (ESO) method [21,22] and others [23][24][25], have been developed. To a great extent, structure synthesis methods of spatial compliant mechanisms are faced with many complicated factors, especially the following two main issues.…”

Isogeometric Bi-Directional Evolutionary Structural Optimization

“…Since the pioneer work of Bendsoe and Kikuchi [1], TO has been widely used to solve the problems in mechanical [2] and many other engineering domains, such as fluids [3], acoustics [4], heat transfer [5], optics [6], multiphysics [7] and functional material design [8]- [10]. Many subsequent approaches have been proposed to solve TO problems in the past thirty years, such as homogenization method [1], solid isotropic material with penalization (SIMP) approach [11], [12], level set method [13]- [17], and evolutionary structural optimization (ESO) approach [18], [19]. Among these, the ESO method is one of the most popular TO approaches due to its simple concept of gradually removing…”