Simulation Analysis And Improvement Of Car Ride Based On ADAMS/Car

Vehicle is a dynamic system, which can respond to the activation of input. The response characteristic determines the value and direction of the vibration on the driver. The response also determines the feel of the driver. The roughness of the road and the speed of car form the inputs of the car vibration system. The inputs pass the transfer of vibration system that composed by tire, suspension, seat and so on. The output of the vibration system is the acceleration of seat. The value of acceleration can be used to evaluate the response of the body to the vibration. The paper also considers the value of suspension working space and the value of dynamic tire load. They respectively influence the probability of striking and the safety of driving.The paper has built complex car model for ride analysis using ADAMS/Car and the model has simulated on the random road and pulse road. On the basis of ISO2631-1 and our country's ride evaluation system, the integrate evaluation method has been confirmed and evaluate on the results of simulation. Above all, the paper has analysed the factors of influencing ride and summarized the tendency. Using the methods of frequency domain analysis and time domain analysis, the paper has brought forward the scheme of improving ride and has simulated to validate the scheme. The important content of the paper is the analysis of vehicle dynamic system, including the system transfer characteristic and the factors of influencing transfer characteristic and the improvement of car ride. The main contents are as following:The main aim of second chapter is to confirm the methods of ride evaluation. The paper has researched the methods of ride evaluation, including the subjective evaluation and impersonal evaluation. ISO2631-1 has been researched and two general ride evaluation methods have been summarized:1/3 frequency band evaluation method and weighted evaluation method. Our country has brought forward the evaluation methods on the basis of ISO2631-1. The paper has confirmed the summarized ride evaluation methods: r.m.s.Value of weighted body acceleration, r.m.s.Value of Suspension Working Space and r.m.s.Value of Dynamic Tire Load.The main text of chapter three is to build the complex car model for ride analysis using ADAMS/Car. The paper has researched the theory of ADAMS/Car and the assemble methods among the templates of suspension and body and so on. The front suspension, rear suspension and body templates have been built. The paper has introduced the trials of important parts for ride analysis, including spring, damper, seat and so on. The nonlinear characteristics are considered to make the model to be closer to the real car.The main content of chapter four is the simulation, analysis and improvementof car ride. The paper has researched the generation of random roads and simulated on the random road and pulse road according to the country standards. The evaluation has been made on the results of simulation.The ride analysis has been made on the results of simulation. The paper has researched on the full car transfer characteristic and analysed on the vertical vibration, pitch motion, longitudinal impact. The factors and the tendency of influencing ride have been analysed. On the analysis of vertical vibration, the full car has been simplified to two-freedom model. The factors of influencing vertical vibration have been analysed, including undamped natural frequency, suspension stiffness, damping and so on. Some conclusions have been made and used to improve the car ride. On the analysis of pitch motion, the analysis has been made on the factors of influencing pitch motion, including undamped natural frequency and damping of suspension. The changes have been made on the full car model to search the rules. For the longitudinal impact, the influence of bushing has been researched.On the basis of ride analysis, the improvement method has been brought forward. The stiffness of spring and the damping of damper have been changed. Finally, the improved car model simulates on the different roads and the simulation results have been contrast to original car model. The aim of contrast is to validate the improvement.The chapter five is the conclusions and the further work.