Optimum Design Of Lattice Structures And Mechanical Properties Based On SLM

With the vigorous development of selective laser melting(SLM) technology,it has laid a foundation for the manufacturability of lattice structure.As a new type of lightweight super-tough structure,lattice structure has attracted close attention in aerospace,sports and biomedical applications due to its excellent mechanical properties and functional characteristics.However,the researches on lattice structure at home and abroad mainly focus on the mechanical properties and failure analysis of simple lattice structure,and there are few researches on the optimal design of lattice structure.In the actual situation,the lattice structure is mostly “bending dominant structure”,so its bearing capacity is still relatively low.Therefore,it is especially important to study the equivalent mechanical model of the lattice structure and optimize the structure.In this paper,the body-centered cubic(BCC) lattice structure was taken as the research object.The equivalent mechanical model of BCC lattice structure was constructed based on the Gibson-Ashby model,and the structural parameters that affect the properties of the equivalent elastic modulus E~* and the initial yield strength ?~* of the lattice structure was obtained.Based on SLM technology,the lattice structure and standard tensile parts were prepared by 316L stainless steel,and the microstructure and fracture morphology of the tensile parts was observed by scanning electron microscope(SEM).Therefore,the mechanical properties of the parameters were evaluated and the internal forming quality of the parts was evaluated.The lattice structure of different structural parameters was simulated by ABAQUS software.The influence of structural parameters on the compression performance was investigated,and the correctness of the theoretical prediction model was verified.The sizing optimization design was carried out based on the BCC lattice structure.The BCC lattice structure sizing optimization model was obtained that made the bar diameter as the design variable,the volume of lattice structure as the objective function,the SLM forming process and displacement as the constraints,and the maximum stiffness and relative density as the evaluation index.The lightweight design of the lattice structure was realized that based on the strength was basically unchanged but the quality of the model was reduced.The model was reconstructed after the size optimization,and the correctness of the optimization results was verified by the simulation method.In addition,the sizing optimization design of BCC lattice structure was designed to obtain the lattice structure with good mechanical properties and fatigue performance,which provide reference for the optimization design and theoretical research of lightweight lattice structure.