A Research On Topology Optimization Design Of Large-scale Box Structure

The large-scale box is a common structure in the mechanical equipment. The traditional design method leads to the heavy structure and the material waste of the large-scale box. So it is necessary to study its lightweight design. With using topological optimization design theory and method, the large-scale box structure is the research object in this paper. The analysis of the large-scale box structure topology optimization design method, the topology optimization model, topology optimization procedure, phenomenon of checkerboard and topological optimization parameter selection are done. Then, two different geometrical dimension of large-scale box structure topology optimization design is completed, and the results of new types of box have the guiding value, providing the design reference for the series of large-scale box structure design. The main research process and results are as follows:1、With analyzing a variety of large-scale box structures, its structural characteristics are extracted, and by analyzing the characteristics of various topology optimization method, the variable density method is selected for the large-scale box topology optimization design.2、Based on variable density method, the mathematical model of the volume constraint, force and displacement constraints, and their sensitivities, are analyzed respectively. According to the weight method, multi condition topology optimization mathematical model of the large-scale box structure is constructed to the load position uncertainty condition.3、The topology optimization program based on MATLAB language and on the C++ program language are researched respectively. The 8 node hexahedron element is used for finite element analysis of large-scale box structure, and the design variables are updated using MMA algorithm and OC criteria method that are suitable for the large-scale box. The PETSc parallel computing topology optimization program which can calculate large-scale nodal freedom degrees is analyzed and tested, which is used in the design of the large-scale box.4、A model is used to analyze the phenomenon of checkerboard in the topology optimization, and the method of density filter, sensitivity filter and gray scale filter are introduced to reduced it by comparing with different filter results. The penalty factor and the filter radius are selected for the topology optimization of large-scale box structure by the method of case verification.5、Considering different filters and the design variable update algorithms, two different sizes of the large-scale box structure topology optimization design are completed under single and multi load conditions by different topology optimization procedure, and the structural characteristics of the optimization results which are same are obtained. This result provides a reference for the series of the large-scale box structure design.This paper has a certain reference value for the innovative design, research and development of large-scale box structure.