The determination of the optimum position of bushing in the trailing arm of torsion beam suspension considering the performance of whole vehicle

Abstract

Torsion beam suspension is used extensively in the rear suspension of the vehicle. The suspension is connected to the vehicle body by the bushing of the trailing arm. In the early stages of design, determining the position of the bushing to provide the vehicle with good performance is important. Based on this, this study explains the influence of the position of the bushing on the performance of the vehicle theoretically. In the simulation study, this paper establishes the hard point m in the multi-body dynamics model and converts the coordinates of the m into angles α and γ to describe the specific position of the bushing. This method is based on changing the coordinates of m to obtain the corresponding position of the bushing and making it possible to investigate the influence of the position of the bushing on vehicle performance within a certain design space. The influence of the specific position of the bushing on the evaluation indexes of the simulation tests including constant radius cornering and the ride comfort on bump road is further investigated. The simulation results show that each index has significant differences with different α and γ. For a single evaluation index, it is possible to find a set of α, γ to make it optimal within the design range, but not all the indexes can be made optimal with the same α, γ. To determine the position of the bushing that will provide the vehicle with better performance, this paper takes the coordinates of m as the optimization variables and the evaluation indexes as the optimization objectives to carry out multi-objective optimization with NSGA-II, NCGA, and MOPSO algorithms. Three specific positions of the bushing that satisfy the optimization requirements are finally obtained.