The Research Of Handling Stability Optimization In A Class Vehicle Based On Rigid-flexible Coupling Method In Suspension Structure

The vehicle handling and stability is an important parameter to evaluate the vehicle comprehensive performance.It reflects the characteristic of sensitiveness and stability when the driver give an order to control the vehicle or the vehicle have an affect on disturbance by external factor. With the development of automobile industry in our country, the requirement of the vehicle increased continuously,puts forward the new requirements for the performance of vehicle handling and stability,because of the vehicle handling and stability is not only affect the performance of control the vehicle but also affect on safety performance when the vehicle driven.Analysis and improvement the factors that affect operating stability characteristicshas important practical significance for vehicle research and development in the process of improving vehicle operating stability.The vehicle contact ground by suspension mechanism, kinematics and compliance properties of suspension system affect the vehicle’s operation stability directly,when the suspension system treated as an important part of the chassis.In this paper, the multi-body dynamics software and finite element analysis software,contrapose large deformation parts in the process of suspension movement,build the coupled rigid and flexible model of front and rear suspension after analysising the front and rear suspension structure.Adjustment original state of the model in order to simulate the actual state of the vehicle as far as possible,and then analyse the KC characteristic of front and rear suspension. Comparing KC test data of design vehicle with simulation model to verify the accuracy of modeling.Then analyse the KC characteristic affect on vehicle handling and stability.Based on vehicle dynamics model is established,choose the steady state cornering test that can response for steady state resonance characteristics and transient response test include step response test and pulse response test that can response for transisent state characteristics,to carry on simulation test according to national standard GB-T 6323-1994, then evaluation the score for the simulation test.According to the score of simulation we found that the score of pulse response test is on the low side and the level of resonant peak level is on the high side. Aiming at the problems existed in the experiment,by analysing spring、shock absorber、tire affect on vehicle handling and stability,to comprehend which is the sensitive factor for transient response time and frequency characteristic of the vehicle.The results show that the change of tire cornering stiffness can cause severe reaction on vehicle handling and stability characteristic,and the different vehicle handling and stability characteristic exist irreconcilable conflict.Based on research the parameters of the spring stiffness, shock absorber damping, steering system, provide some suggestions for optimizing vehicle operating stability characteristics.