Topology Optimization Method And Its Applications In Micro-compliant Mechanism Design

Topology optimization is an important approach in structural optimization, through which better schemes can be chosen in concept design stage. Compared with shape and size optimization, it is considered as the most difficult and challenging problem.From the design of micro compliant mechanisms, this thesis investigates the design problem of compliant mechanisms using continuum structure topology optimization method. The reasons and methods to solve numerical instabilities in topology optimization are discussed. The optimization model for structural stiffness and the multi-objective model for compliant mechanisms are proposed. Based on topology optimization method, piezoelectric driven micro-gripper is designed and tested.Based on FEM and Matlab platform, structural topological optimization is implemented using the FEM program by the author, combined with MMA optimization method. Mesh-independent filter method is used to solve the checkerboard pattern and the mesh-dependent problem. Using the method of continuation of the filter radius, local minima problem is avoided. The results show that these methods are very efficient in solving instability problems. Structural stiffness topology optimization under multiple load cases is solved through examples. The topological optimization model of compliant mechanism has been modified and its convexity has been analyzed. Through calculation examples, the model is verified. The experimental results of piezoelectric micro gripper are well coincident with the FEM calculated ones. Displacement and clamping fore of gripper are well linear with the control voltage, and the relation formulations are derived.It can be obtained from this thesis that continuum topology optimization is methodological for optimal design of micro compliant mechanisms and is of promising widely use.