Optimization Of Twist Beam Suspension And Analysis Of Vehicle Handling And Stability

Handling and stability is an important vehicle property. It reflects the ability of the vehicle in response to the driver’s instructions exactly, and the ability to restore the original motion state when the vehicle is disturbed. Suspension is an important part of the chassis.The K&C characteristics affect handling and stability significantly. Because of the simple structure, low cost, and has more advantages in kinematics, the twist beam suspension is widely used in family cars. It is an important means of chassis developing. Simulating and optimize the twist beam suspension, and evaluating vehicle performance is an important means for chassis positive development.This thesis is to optimize the twist beam suspension and analysis the handling and stability of an electrical car. The twist beam suspension and vehicle model were built by the dynamic software ADAMS/Car. Optimized suspension characteristics for twist beam suspension hardpoints and bushing stiffness parameters, then analyze vehicle handling and stability. The results show that the optimization can provide a good vehicle handling and stability.First, this paper analyzed the structural characteristics of the twist beam suspension. It established rigid and flexible coupling twist beam suspension and MacPherson front suspension model, and built a vehicle model with other subsystems. Based on the initial twist beam suspension, tested and analysised the K&C characteristics, then analyzed the trends of toe angle, camber, wheel lateral displacement and vertical displacement parameters. The results proved that the initial design of the twist beam rear suspension basically meet the design requirements. To ensure that the vehicle has good handling and stability, suspension K&C properties need to be further optimized.Then, according to the suspension K&C characteristics, using response surface method to test and analysis the suspension hardpoints and bushing stiffness sensitivity. Selected some important hardpoint coordinates and bushing stiffness as the optimization factors by the result of sensitivity. The optimal solution obtained with method of improved non-dominated sorting genetic algorithm. By contrasting suspension characteristics before and after optimization, it was verified that the optimization can effectively enhance the suspension characteristics.Finally, based on the twist beam suspension has been optimized, to typical test of handling and stability, such as steady static circular test, corner and self align teat, step steer test. According to the index of vehicle handling stability limits and evaluation method, analyzed the evaluation of the tests. The results proved that the car has good handling and stability.