Research And Applications On Structure Optimization Based On Evolutionary Algorithm

Structural optimization is of great importance to the design of mechanical products.The types of structural optimization may be classified into three categories,i.e.size,shape and topology optimization.Topology optimization is applied in the concept design stage of a product,aiming at obtaining the optimal topology structure that meets the performance requirements,which is of decisive significance to the structural form and functional characteristics of the product.In this paper,a three-dimensional continuum structure is used as the topological optimization object,on which some static and dynamic optimizations are conducted based on BESO method.Then,applying this method to the optimization of damping distribution on the surface of thin-walled structures,the optimal distribution of the damping layer on the thin-walled structure was obtained.Based on the above research,a topology optimization system is developed which achieves the static and dynamic topology optimization of 2D and 3D continuum structures.Firstly,based on the basic theory of finite element analysis,a FEA modal for three-dimensional continuum structure is established.After studying the theory and evolutional strategy of the BESO method,the basic iteration procedure is summarized.The topology optimization of 3D continuum structure based on the maximization of stiffness is studied,and the effectiveness of this method is verified by the example of Cantilever beam optimization.Secondly,the application of BESO method to dynamic optimization is studied.With the comparision of several material interpolation models,the Polynomial Interpolation Scheme is applied in the dynamic optimization.The natural frequency and global frequency response optimization are conducted,the natural frequency maximized and global frequency response minimized are achieved.Applying the BESO method to the optimization of the damping layer on the surface of thin-walled structure.Based the MSE method,the optimization model to maximize the modal loss factor was established.The sensitivity of the objective function to the design variables with the Polynomial Interpolation Scheme was deduced.After optimization,the damping layer distribution was obtained,and the purpose of vibration reduction was achieved.Finally,using MATLAB software to develop a topology optimization system for 2D and 3D continuum structures,which achieves topological optimization of 2D and 3D continuum structures,and can export the optimization results to 3D print files,achieving additive manufacturing.Detailed description of the system implementation process,system architecture and data structure are presented,and the feasibility of the system was verified through examples.