Study On Topology Optimization Design Of Periodic Continuum Structures

Periodic structures are highly profiled by designer with its unique configuration,good manufacturing and excellent mechanical behavior. The traditional design methodabout geometric configuration of structures is rely on experience and subjectivethinking of engineers, or make a size and shape optimization to it. As the requirementsof light-weight structural design being enhanced, the traditional design method istime-consuming, the development potential of it is limited. Topology optimization isone method of material layout design, this method can get the optimal material layoutand plays material’s carrying capacity fully, and fundamentally can propose aimprovement project for structures. Topology optimization has become one of keytechnologies of modern structure design. In this paper, the periodic structures’characteristics, types and applications were firstly introduced. Then the developmentprocess and mainstream approaches of topology optimization techniques, the field oftopology optimization research and research status of it in periodic structures designwere reviewed. On this basis, based on SIMP material model and combined with theimproved density slope control algorithm, a topology optimization model of periodicstructures was established by the technology of variables associated. Theconfiguration design of planar grid stiffened structures, revolving rings and slenderbeams were investigated.Considered the grid stiffener’s feature, an approach for the design of stiffeners ofthe solid FEM model was proposed. Used the unit mass-stiffness as the evaluationindex, the influence rules of grid configuration and performance were analyzed bychange the skin thickness, stiffener height and percent of material used. The result’saccuracy of topology optimization was verified by make a model reconstruction andsize optimization using ANSYS. The size effect of periodic structures was revealed byanalyze the changes of optimal configuration and structure performance of one ortwo-ply grid stiffened structure, there was double size effect upon the designconfiguration and performance of grid stiffened structure in which take into accountthe free vibration.Configuration design of rings that with three typical arbitrary loads werediscussed for static stiffness optimization problem, the critical module number of sizeeffect was different between the three loads. By studied the change law of unit mass-stiffness of ring along with the diameter ratio, diameter ratio larger the structureefficiency is lower. Then, through established a sandwich ring structure model, theinfluence of skin and its thickness changes upon sandwich configuration was analyzed,and pointed out that the design of inner and outer skin thickness need to be accordingto the load conditions.Researched the slender cantilever configuration design that with repetitiveassembling components. Considering the repetitive module number must be an integer,optimal configuration and structural stiffness were discussed using the way ofenumeration, the results show that there was an optimal module number (optimalsub-module design domain aspect ratio) for configuration design for a slendercantilever that has been given length and width. The results’ correctness was verifiedby make a size optimization. Finally the material distribution ratio was analyzed.