Vibration Mechanism And Optimization Design Of Car Torsion Beam Rear Suspention System

As an important part of automobile chassis,torsion beam rear suspension plays an important role in cushioning the vibration impact of road excitation and ensuring the comfort and safety of automobile.As the transmitter and undertaker of force and moment,suspension bears vibration impact produced by engine excitation and road excitation all the time during driving.Drastic vibration,especially resonance,easily cause the dynamic performance of suspension system to become particularly complex.The dynamic performance is not only related to the safety and comfort of the vehicle,but also directly affects the fatigue life of suspension.Therefore,when optimizing the suspension system,it is necessary to ascertain the vibration mechanism of the suspension system under the influence of the whole vehicle and consider the influence of dynamic characteristics.The purpose of this paper is to reveal the vibration mechanism of suspension system and optimize the suspension by synthesizing suspension mass,natural frequency and dynamic response performance index.The main contents are follows:The finite element model of beam element and longitudinal arm element of the torsion beam rear suspension is established.On this basis,considering the interaction between the components of the vehicle,the dynamic equation of vehicle torsion beam rear suspension system is established through the finite element method,which reflects the internal relationship between the dynamic performance of the suspension and the parameters of the structure,material and external excitation.According to the dynamic equation of the torsion beam rear suspension system,the vibration mechanism of the suspension system under road excitation and engine excitation is explored,the vibration law of the suspension system under is analyzed,and the internal relationship between the dynamic characteristics of the suspension system and the structural parameters,material parameters and external excitation parameters is proved.Based on the analysis of dynamic characteristics of suspension system,the sensitivity expressions of natural frequency and displacement response to structural parameters of suspension system are derived by combining analytical method and differential method,and the sensitivity of dynamic performance of suspension system to structural parameters is proved.The key technical parameters in the suspension design process are analyzed.With the optimization design theory and given natural frequency,dynamic stress and boundary constraints,an optimization mathematical model considering suspension mass as the optimization objective and beam thickness,longitudinal arm thickness and beam position as design variables is established and then the optimization method that improve the dynamic performance of suspension syste is determined.The dynamic characteristics and optimization design of the torsion beam rear suspension system are simulated by an example to verify the correctness of the theory research in this paper.