Research On Multi-objective Topology Optimization And Its Application Based On ESO Algorithm

With the rapid development of the theory about finite element and numerical calculation,the topology optimization technology has become a hot research topic in the field aboutstructural optimization design. The much more attention has been paid to the single objectivetopology optimization problem in recent years, but limited effort is put into multi-objectivetopology optimization problem. Considering there are a lot of multi-objective optimizationproblems in the actual structural topology optimization area, multi-objective topologyoptimization algorithm based on ESO and its application on the key components (lathe bed)of deep hole machine have been researched intensively in this paper. The specific content canbe summarized as the following:(1) Based on the function of birth and death function about element, ESO algorithms thatregard the element strain energy and frequency sensitivity as optimization criterion have beenimplemented. According to different design goals, three different kinds of formulas aboutperformance index parameter are deduced respectively, which are used to accurately evaluatethe efficiency of the topology design. Second order smoothing technique for suppressing thecheckerboard patterns has been proposed based on the filtering function’s principle. Researchhas shown that the method can effectively improve the result of optimization.(2) Combining ESO and weighted compromise programming method, a new method foroptimization problem under multiple loading conditions has been proposed, reducing theinfluence of the load failure phenomenon. The multi-objective problem has been studied. Bymaking stiffness and frequency sensitivity normalized and weighted again, the equivalentmulti-objective sensitivity number for static stiffness and natural frequency is obtained, layinga theoretical foundation for optimizing static and dynamic performance at the same time. Classical examples are given and they are shown that the above two algorithms are effectiveand correct.(3) Develop the topology optimization program of multi-objective topology optimizationalgorithm based on ESO with APDL(ANSYS Parametric Design Language)and realized theuser graphic interface design with UIDL(User Interface Design Language),enlarging thefunction of topology optimization inANSYS.(4) Based on strain energy criterion ESO algorithm under multiple loads is applied onlathe bed of Z8016deep hole drilling machine, achieving the lightweight design of lathe bedeffectively. The modal analysis of lathe bed structure was studied by ANSYS software and theresult was shown that lathe bed dynamic performance needs to be improved. Topologyreconstruction design for Z8016deep hole machine lathe bed is studied by multi-objectivetopology optimization algorithm based on optimization goal of maximum stiffness andmaximum fundamental frequency. The purpose of improving the static and dynamicperformance and lightweight design has been implemented effectively. the original structureof lathe bed and optimal one were analyzed by harmonic response, verifying that dynamicperformance of the optimized lathe bed is improved greatly.