Synthesis of Superelastic Compliant Mechanisms for Target Shape and Stiffness Matching
The design freedom of additive manufacturing has potential to increase the complexity, functionality, and mechanical behavior of compliant mechanisms compared to conventional manufacturing methods. However, this same design freedom can result in “trial-and-error” design iteration when designing compliant mechanisms for target behaviors. Trial-and-error design iteration is undesirable and inefficient, particularly when designing compliant mechanisms with nonlinear-elastic materials and large deformations. To address this problem, we develop a synthesis method for the inverse design of compliant mechanisms that uses numerical optimization and a library of building blocks that incorporate nonlinear-elastic materials, and large deformations as geometric nonlinearity. The synthesis method works by selecting the type and geometry of the building blocks that will deflect to a target shape under a given load, or achieve a target stiffness response. The method's ability to use different building block geometries and incorporate nonlinear behaviors, such as the superelasticity of shape memory alloys, is shown to enhance the design of compliant mechanisms to reach target shapes or stiffness responses.