An energy formulation for parametric size and shape optimization of compliant mechanisms

Compliant mechanisms are jointless mechanical devices that take advantage o f elastic deformation to achieve a force ol motion transformation. An impor tant step toward automated design of compliant mechanisms has been the deve lopment of topology optimization techniques. The next logical step is to in corporate size and shape optimization to perform dimensional synthesis of t he mechanism while simultaneously considering practical design specificatio ns such as kinematic and stress constraints. An improved objective formulat ion based on maximizing the energy throughput of a linear static compliant mechanism is developed considering specific force and displacement operatio nal requirements. Parametric finite element beam models are used to perform the size and shape optimization. This technique allows stress constraints to limit the maximum stress in the mechanism. In addition, constraints whic h restrict the kinematics of the mechanism are successfully applied to the optimization problem. Resulting optimized mechanisms exhibit efficient mech anical transmission and meet kinematic and stress requirements. Several exa mples are given to demonstrate the effectiveness of the optimization proced ure.