Structure Design And Finite Element Analysis Of Double-stage Torsion Bar Spring

The unit stored energy of torsion bar spring is much bigger than that of the elastic component of any other kind, and can decrease the under spring mass of automobiles. In automotive suspension, the torsion bar spring is favor of improving manoeuvrability and requires relative small spatial arrangement comparable to other springs. With regard to the linear characteristic of its torsional stiffness, in order to improve further performance of torsion bar spring, this article has carried on structural analysis and design for torsion bar spring.Optimization design has been made on the single-stage torsion bar spring which applies to automotive suspension in this paper, and base on Double-wishbone independent suspension as its installation platform, conducting structural design with utilization of CAD software CATIA on double-stage torsion bar spring. It also has been listed three kinds of structural styles of double-stage torsion bar spring and has analyzed their good and bad points.The stiffness of the traditional single-stage torsion bar spring approximates to constant. Whereas, the double stage torsion bar spring which the thesis researches into has the non-linear characteristics. The nonlinear suspension can reduce the leaning when the vehicles swerve on the way, and also can decrease the front depression angle and back elevation angle, which appears respectively when break and speedup. This article has adopted quite common finite element method in modern engineering design to analyze the performance of torsion bar spring. The finite element model has been established for both single and double stage torsion bar spring by software ANSYS and the static stress analysis have been made respectively. It has drawn two kinds of stiffness curves of torsion bar and the torsion bar spring with stress and strain value, the data obtained from torsion bar spring under different loading. From the result of comparative analysis to the stiffness curves of two kinds of torsion bar spring, it can conclude that the stiffness curve of the double-stage torsion bar spring would be much closer to the ideal spring stiffness curve, promoting the vehicle ride performance and the handling directional stability.