Topology Optimization Method Of Primary And Secondary Frame-bracing Structure Based On ESO Method

Primary-secondary frame-bracing system is a kind of new structural system.As an important component of the system,the arrangement form of brace is varied.The traditional design method is a trial-verify-modify design method.The results obtained by this method are often not optimal,and need to consume a large amount of time and human resources.This paper stud ied the method of topological optimization theory,realized the topology optimization function through the secondary development of the ANSYS impleme ntation.According to the characteristics of the primary-secondary structure,I improved the method,and applied in the conceptual design system of primary structure.Studied the spatial topology of primary-secondary frame-bracing system under different condition of constrains.At the same time,the results of topology optimization were reconstructed by the dimension optimization method,and the mechanical properties were compared with the traditional support layout.Research on topology optimization mechanism and software implementation.Based on the basic idea of the ESO method,the characteristics and basic flow of the ESO method were analyzed.The formulas of sensitivity calculation and performance index were derived under the stress constraint,strain energy constraint and displacement and displacement difference constraints.According to the theoretical formula and implementation flow of ESO method,through the APDL parametric programming language,I made full use of the powerful preand post-processing capability of ANSYS,and developed it in the second time,and realized the topology under different constraints.Finally,I optimized the two-hinged support Michelle-type structure under stress,strain energy,displacement constraints,to verify the algorithm and program.Topological optimization and analysis of primary-secondary structures.In this chapter,the primary-secondary frame structure model with the optimized region was established in ANSYS.The traditional ESO method was applied to the topology optimization of the primary-secondary frame-bracing structure.The difficulties and shortcomings of the traditional ESO method in the topological optimization of the main-frame-bracing system were found through analyzing the optimization process and results.According to the problems discovered,the ESO method was improved.such as the BESO,the sensitivity filter and the symmetrical structure,are introduced respectively.These methods were programmed into the command stream and embed into the program.Optimize d the primary-secondary frame-bracing structure model under stress,strain energy and displacement constraints.Analyzed and compared the result.Reconstruction and analysis of topology optimization of primary and secondary structures.In this chapter,the model of 3D primary-secondary structure with support region was set up in ANSYS,and the topological optimization was carried out to analyze the similarities and differences between 3D structure and 2D planar structure in topology optimization.Based on the parametric dimension optimization method of APDL,the results of topological optimization were reconstructed,the graphic information obtained from topological optimization was transformed into the sectional dimension information,and the control groups were established by three kinds of traditional support layouts,and different support arrangements were obtained of the primary-secondary structure.Through the SAP2000 software,the stress analysi s of each structure under the horizontal load wa s carried out.The effect of different supporting arrangement on the lateral stiffness of the structure and the mechanical properties of the various members was discussed,and the results of topology optimization and size optimization were evaluated.