Structural optimization considering flexibility: Integrated design method for compliant mechanisms

Abstract

In structural design, the stiffest structure is considered optimal. However, flexibility can provide structures with certain advantages in terms of structural performance or additional function such as mechanical function, if flexibility mode can be specified. Compliant mechanism is a new breed of mechanisms which uses the design concept of structural flexibility to achieve a specified motion. In this paper, an integrated structural optimization method to implement flexibility in the mechanical structure is proposed, and applied to the compliant mechanism design. First, structural flexibility is expressed using mutual energy, and a new multi-objective function incorporating the maximum flexibility and minimum compliance is formulated. Next, a design procedure is constructed using the homogenization design method and image based approach. Finally, some examples of designing compliant mechanisms are presented, which confirm that the method presented here can be applied to the compliant mechanism design.