Glass lifter is a key part of automobile door system. Guide rail is the carrier of glass lifter, and it bears various load cases when glass lifer works. Mass, stiffness and natural frequencies are the factors that influence the performance of glass lifter. In order to design a lighter and reasonable glass lifter, topology optimization methods are studied in this paper.
In a rope-wheel glass lifter, design domain is determined by the mechanical structure and working conditions. Firstly, the single target continuum structure topology optimization mathematic models of guide rail are built in this paper, and analysis of multi-stiffness topology optimization are carried out accordingly in which volume fraction is set as 0.4, 0.5 and 0.6. These models are based on SIMP (Solid Isotropic Material with Penalization) theory. Secondly, multiobjective topology optimization models of guide rail are built to consider the influence of dynamic characteristics, and volume fraction is also set as 0.4, 0.5 and 0.6. These models are based on the weighted compromise programming approach. A new formula is proposed in this paper, and optimization objectives are static stiffness and dynamic frequencies, constraint is volume fraction.
Comparing these two methods, single target optimization method is more efficient, whereas the structures of optimized guide rail are not reasonable due to the appearance of a large minimum density area in the middle of guide rail. The topology optimization method of considering dynamic characteristic makes the structures of the optimized guide rail more reasonable. The structural load path is clear, and more triangular structures generate which strengthen stiffness of the structure. In addition, values of optimized compliance are lower than that of the single target topology optimization and the first three order frequencies of multi-objective topology optimization are higher than that of single target. So the topology optimization method of multi-objectives makes guild rail have better rigidity and vibration characteristics, which provides a valuable basis and method for the design of guild rail.