Abstract
This paper presents an investigation on the optimal design of planar flexible linkages. The whole linkage is modelled as an assemblage of finite elements. For the optimal design of mechanical systems is a special case of optimal control problem (OCP), the software system OCP is employed to solve the optimal design problem. It is different from the methods proposed by the earlier researchers. An example is presented that under constant crank speed, the weight is to be minimized while the deviation of coupler point is constrained. The modal analysis is used to verify the dynamic response of the optimal design. From the results, the weight is reduced much while the dynamic response still satisfies the design requirements.