An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms under Various Design Criteria

This paper covers topology optimization of fully compliant structures using beam elements. The swarm intelligence technique known as Ant Search (AS) is used to find the optimum design that satisfies the required mechanism performance. A fully compliant micro-structure that involves the topology design of a miniature displacement amplifier is studied and results are validated with the finite element solver ANSYS. Four different case studies are presented where the mechanism is optimized for different design criteria that involve maximizing the amplification ratio, maximizing the output displacement, and minimizing stresses. Unlike previous work in literature, each design variable is assigned an ant where the optimization is not limited to the existence of a void or material element but extended to the dimensions (width and thickness) of each element by itself. The results produced in each case are compared to those presented in the literature where significantly larger amplification ratios and output displacements were achieved as compared to those previously reported in the literature. These results show the high potential of swarm intelligence and AS in particular at solving multidisciplinary optimization problems that should not be limited to designs with physical paths. (C) 2017 Elsevier Ltd. All rights reserved.