Design Of High Speed Transporting Equipment Based On Structural Topolo-Gy Optimization Theory

Automobile body welding line is a crucial part of automobile production.In recent years, with the rapid growth of domestic car market, high speedwelding lines, whose production is above200thousand automobile bodies,are urgently needed. High speed transporting pallet is the heart of high speedwelding line and it is responsible for transport car bodies and fixtures withinvery short time. Because of short operational time, high speed transportingpallet has to be light in order to reduce driving load of system.The topology optimization method is a new structural optimizationmethod developed on the basis of the finite element analysis methods andhigh-performance computing tools. The optimal topologies distribution of thematerial within the design space can be calculated with the objectives such asstructural stiffness, mass, heat transmission under the constraints with thestrength, mass or natural frequencies. In the past decade years, many effectivemethods are proposed including the homogenization methods, interpolationmethod of material density, evolutionary optimization method. They arewidely used in the fields such as automotive and aerospace industries. How-ever, some numerical problems appear when these methods are used in the re-al structures.In this paper, basic mechanical and mathematical theories are employedto study the mathematical model of the topology optimization. The alterabledensity method and optimization criteria are discussed. By using the softwareMatlab, the instability of the topology optimization is studied using the filter-ing algorithm. The high-speed transportation pallets are employed to investi-gate the strength and optimization design considering the variable constrainsacted on it. The structural performance is effectively improved while reducing the mass of material. It is very useful for the topology optimization to be usedin engineering structures.Firstly, the finite element method on the numerical solution is deducedcombined with the basic equations of elasticity and partial differential equa-tions. Then, the interpolation model of material with alterable density methodand optimization algorithms are discussed. The mathematical models andnumerical model of the topology optimization problem is established. Thecorresponding program codes are written by using software Matlab.Then, the numerical instability phenomenon in the calculation of topol-ogy optimization is investigated based on the program codes. The correlationbetween the numerical problems in the calculation and the filtering radii arediscussed. The results show that it has great influence on the topology shapeof structures.Finally, the strength and stiffness of two important parts and the entirestructure are studied for the high-speed pallet. The optimization method isused for this devise because the deformation of pallet is greater than the re-quirement of design. Here, the objective is that the mass is minimal. And con-strains are the deformation of pallet. The topology optimization are conductedconsidering twelve types of constrains. The new design strategy for the palletis proposed in terms of the optimization results. The verification has beendone for the new design. The results show that the strength and stiffness cansatisfy the requirement. There is22.6%material savings compared to theoriginal design.