Dynamic Topology Optimization Of Compliant Mechanism

This thesis is based on the project of National Natural Science Fund of China (50375051), Natural Science Fund of Guangdong Province (036548) and Institution of Higher Education Outstanding Young Teacher Teaching Scientific Research plan rewards, which deeply research on dynamic topology optimization of compliant mechanisms using homogenization method.According to the design method of topology optimization is mainly based on static state at present, the research about topological optimization design of dynamic problem is still very Limited, A dynamics topology optimization method for compliant mechanism considering both of the flexibility and stiffness of the system based on the homogenization method has been developed in this thesis.First, the finite element method is combined with homogenization theory based on asymptotic expansion for prediction the macro and microscopic propertics of cellulaer materials.Through the use of asumptotic expansion of the displacement,the control equations of periodic micro-structure are established and the relationship between homogenized elasticity tensor and microscopic structure demension was also established, then the homogenization FEM for analyzing two dimensional periodic materials is developed.The following study is optimizing models using the criteria method. The proposed element removal scheme incorporating the frequency contraint with "nibbling" technique is capable of increasing the fundamental frequency of the structure and improving the details of the final topology. the corresponding optimization implementation method and procedure flow chart have been presented. Three unstable phenomenon about value existing in the course of real optimization have been solved. Finally, two design examples are presented to illustrate the validity of the method.