Shape and Topology Optimization of Compliant Mechanisms Using Level Set-based Parameterization Method

A new parameterization approach 1 for optimal synthesis of compliant mechanisms using level set-based shape and topology optimization approach is presented in this work. The structural free design boundary is implicitly represented by embedding into a higher-dimensional scalar function as its zero level set. The compactly supported radial basis function with a favourable smoothness is introduced to construct the trial function. Structural optimization is advanced by iteratively evaluating the optimization problem using a sequential convex programming scheme. The coefficients together with the collection matrix of the radial basis functions are then utilized to renew the level set function by performing the size optimization. Therefore, the presented method is capable of addressing shape fidelity and topology changes simultaneously, especially with the capability of keeping design boundary smooth during the optimization process. Optimal synthesis of compliant mechanisms is applied to demonstrate the potentials, in which the mechanical efficiency is treated as the objective function, while the limitation of the maximal input displacement and the prescribed material usage are treated as two global constraints to further narrow the design domain. A benchmark example is applied to demonstrate the benefits and the advantages of the proposed method.