Analysis On Rollover Stability Of Dual-front Axle Automobile Based On Virtual Prototype Technology

Automotive rollover stability means all wheels can keep contact with ground in motion process. With the steady growth of national economy, the mount of dual-front axle tractors has increased rapidly. The dual-front axle tractors have higher gravity-center and relatively narrow tread in comparison with the height of gravity-center, therefore the rollover threshold of dual-front axle tractors is lower, which means the rollover stability of dual-front axle tractors is poor. Meanwhile, the vehicle rollover issues referring to the rollover stability of dual-front axle tractors have become an important cause restricting the security of traffic and transportation. In this paper, combined with a university-enterprise cooperation project, the principle of roll and the structure parameters and driving parameters which have impact on dynamic rollover stability of dual-front axle tractors were analyzed. The research results can be used to provide theoretical reference for automobile manufacturing enterprises in the process of developing products. The study was carried out as follows:Firstly, the common evaluation indexes of rollover stability (body rollover angle, lateral acceleration and LTR) and experimental methods were introduced. Roll mathematical model was built. Then the roll mathematical model was analyzed to get the motion and structural factors which can influence its rollover stability, which can provide theoretical foundation for the study of rollover stability of dual-front axle tractors.Secondly, based on a dual-front axle tractor in this paper, a virtual prototype model including steering system, front/rear suspension, driving axle, powertrain, frame, tires and leafsprings subsystems was built in ADAMS/Car.Finally, the steering wheel angle step tests were carried out using the virtual prototype model in accordance with the national standard requirements. Motion parameters (speed and steering angle) and structural parameters (height of mass center, vehicle load, front/rear tire cornering stiffness, damping coefficient and axle base) were chosen to analyzed as several key influential factors on the rollover stability of dual-front axle tractor.