Influence Of Torsional Stiffness Of Leaf Spring On Vehicle Handling Stability

With the development of automotive industry technology,people have higher and higher requirements for vehicle handling stability.Leaf springs,as the most widely used elastic components in commercial vehicles and some passenger car suspensions,play an important role in the handling stability of automobiles.At the same time,the design of the car gradually tends to be lighter.For the leaf spring,the lightweight design is mainly to replace the multi-leaf spring with a small leaf spring,so as to reduce the quality of the car,improve the power of the car,and reduce Fuel consumption reduces the purpose of exhaust pollution.However,the current research on the steering stability of the car mostly focuses on the influence of the vertical stiffness of the elastic element on the roll stiffness of the suspension,while ignoring the torsional stiffness of the suspension when the leaf spring is used as the elastic element.The influence of the different torsional stiffness of the small-section variable-section leaf spring and the multiple leaf springs on the stiffness of the suspension roll will affect the design of the lateral stabilizer bar of the leaf spring suspension,which will adversely affect the steering stability of the car.It is also not conducive to the promotion of a small piece of variable-section leaf spring.This paper has carried out related research on the above problems,and the research work and innovative research results are as follows:(1)Based on the analysis of the torsional stiffness mechanics model of the equal-thickness rectangular section beam,combined with the Cartesian second theorem,the analytical formula of the torsional stiffness of the monolithic equal-thickness leaf spring is established.On the basis of this,by analyzing the relationship between the moment and the deformation of the leaf spring during torsion deformation,the analytical calculation formulas of the torsional stiffness of the small-section variable-section leaf spring and the torsional stiffness of the multiple leaf springs are established respectively,and the torsional stiffness of the leaf spring is simulated by ANSYS.(2)Based on the parameters of a passenger car,a multi-body dynamics simulation software ADAMS is used to build a multi-plate spring suspension vehicle model and a small-sized variable-section leaf spring suspension vehicle model,and perform angular step steering simulation,ramp pulse steering simulation,Single shift line simulation and drift simulation,comparative analysis of simulation results,evaluation of vehicle handling stability,analysis of the impact of leaf spring torsional stiffness on vehicle handling stability.(3)Based on the study of the torsional stiffness of the leaf spring,combined with the calculation method of the roll pitch stiffness of the suspension,the analytical calculation formula of the roll-angle stiffness of the leaf spring suspension is established,and the lateral stabilizer bar of the leaf spring suspension is optimized and designed by the simulation software ADAMS.The design method of the leaf spring suspension lateral stabilizer bar was verified.Through the dynamic simulation software ADAMS,the vehicle model is established and the vehicle steering stability simulation is carried out.The simulation results of the vehicle model with different torsional stiffness leaf springs are compared.The steering stability of the vehicle is evaluated and the torsional stiffness of the leaf spring is analyzed.The impact of the steering stability of the car.Finally,from the perspective of improving the driving safety of the whole vehicle,considering the torsional stiffness of the leaf spring,the lateral stabilizer bar of the small-section variable-section leaf spring suspension is optimized to improve the driving safety,and the lateral stability bar of the leaf spring suspension is simulated and verified.The design method is correct.This research has important theoretical guiding significance for the lightweight design of leaf springs,the promotion of small-section variable-section leaf spring suspensions in commercial vehicles and the design of lateral stabilizer bars for leaf spring suspensions.