Research On Thermo-mechanical Coupling Topology Optimization Of Periodic Structure Based On Meshless Method

Composites with excellent mechanical and thermal properties have been widely used in thermal equipment and power machinery and other fields.The periodic structure has unique form,convenient manufacture and beautiful appearance.The assembly process of structural system can be simplified by periodic component splicing,which has good practical value.Therefore,it is of great theoretical and practical significance to carry out multi-objective periodic optimization design of composite structures considering the bearing and heat dissipation performance of the structure.The topological optimization method breaks away from the previous rigid design process,and can obtain the structure form satisfying the designer's requirements while shortening the design time,which has good research value and application prospect.In this paper,the topological optimization theory is introduced into the periodic optimization design of composite structure based on the Element-free Galerkin(EFG)Method,and the kind of problem is studied.The main research contents include(1)The periodic structural topological optimization model of orthotropic materials was established based on EFG method and the solid isotropic material with penalization(SIMP)model.The model is used to obtain the optimal periodic topological configuration of orthotropic material structure under mechanical loading,and the influences of the number of design subdomains,Poisson's ratio factor and off-angle on the EFG optimal periodic structure and structural compliance are discussed.A group of optimal parameters are selected to carry out periodic optimal design of anisotropic and isotropic structure,and the static analysis and comparison of the optimized structures are carried out based on EFG method,which verifies the effectiveness of the topology optimization model.(2)The topological optimization model of thermoperiodic structure of orthotropic materials was established based on EFG method and SIMP model.The effects of the number of subdomains,thermal conductivity factor and off-angle on the EFG optimal periodic structure and heat dissipation are discussed.A group of optimal parameters are selected to carry out periodic optimal design of anisotropic and isotropic structure,and the heat transfer of the optimized structures was analyzed and compared by EFG method.The results show that the anisotropy optimization obtained by using EFG thermal periodic structure topology optimization model has better thermal conductivity,lower working temperature,lighter weight and periodic material distribution.(3)The multi-objective periodic structure optimization model for thermo-mechanical coupling of orthotropic materials was established based on EFG method and SIMP model.The model was used to optimize the structure under mechanical and thermal loads,and the influences of weights,number of design subdomains,Poisson's ratio factor,thermal conductivity factor and off-angle on the EFG optimal multiobjective periodic structure,weighted objective function,compliance and heat dissipation were studied.A group of optimal parameters are selected to carry out multiobjective periodic optimal design of anisotropic and isotropic structure.The static analysis and heat transfer analysis of the optimized structure were carried out by using EFG method,which reflected the advantages of EFG topological optimization method and composite structure.In this paper,the meshless method is used to study the periodic topology optimization of the composite structure under the action of mechanical load,temperature load and mechanical load together with thermal load.The periodic structure with excellent bearing and heat dissipation properties is obtained,and the structure is lightweight.The research has good theory and engineering application value.