Variable Density Topology Optimization Method And Its Application In Radial Steel Gate

With the development of the times,the competitive pressure of the enterprises is increasing,and the economic design of the structure has become the goal of the enterprises under the premise of ensured safety of the structure.At the same time,the optimization design theory has been improved,and structural optimization design has become a very important concept in the scientific research and engineering.Structural optimization design is divided into size optimization design,shape optimization design and topology optimization design.The topology optimization design is difficult to achieve,and still in a period of rapid development.The researches on topology optimization method are becoming deeper and deeper.At present,many topology optimization methods have been proposed,in which the variable density topology optimization method is simple and easy to understand.It is also easy to program this method in MATLAB and the basic MATLAB program corresponding to the basic theory of the variable density topology optimization method is available.So this paper will study on variable density topology optimization method.Numerical instability phenomena,such as the gray unit,checkerboard and mesh dependence etc,are important aspects under consideration in the research of variable density topology optimization method.Therefore,in this paper,the variable density topology optimization method is improved,and the topology optimization theory is applied to practical engineering.The main contents of this paper are as follows:1? This paper introduces the common optimization methods in ANSYS,and the numerical results of a structural size optimization problem proved the advantage of the first order optimization method.The process of topology optimization in OPTISTRUCT is also introduced.Besides,the paper analyzes how to adjust the topology optimization parameters to obtain the best design in OPTISTRUCT based on two examples.(Chapter 2)2? This paper introduces the theory of variable density topology optimization method and the core ideology and implementation process of several filtering methods in literatures.An improved function is put forward based on Heaviside function for the volume preserving density filtering method.The volume preserving improved function has simple form and is easy to program.It is also proved that the volume preserving improved function is more effective than volume preserving Heaviside function to punish the density of the element.Three examples are given to demonstrate that the volume preserving density filtering based on improved function can not only inhibite thenumerical instability phenomena such as grey element,chessboard etc;but also ensure a smaller compliance of final optimized structure.(Chapter 3)3? The topology optimization theory is applied to practical engineering--design of steel arch gate.Two kinds of gates are proposed based on the result of topology optimization,the shapes of whose arm are respectively herringbone support arm and supporting-beam-connecting-beam arm.And through comparison of these two kinds of steel gates and the steel gate designed based on codes,it is proved that the two kinds of steel gates designed based on topology optimization are both lighter than the steel gate designed by codes,and the decreased volume is about 38%.The optimization effect is obvious.Besides,the herringbone-support-arm steel gate designed by topology optimization has the most reasonable structural arrangements and the lightest weight.(Chapter 4)...