Simulation Study On Maneuvering Stability Of All - Terrain Vehicle Based On Rigid - Flexible Coupled Suspension

Utility terrain vehicle(be called UTV for short), is a kind of no license plate but mult-ifunction vehicle, which is widely used in entertainment, farm, military and special topo-graphy. It has a booming market demand, the competition of domestic and international market is also fierce unprecedented. With the widely use of the UTV,people put forward higher requirements for the handling stability performance,driving safety performance and vehicle running smoothness. Using the knowledge of multi-body dynamics and virtual proto-typing technology, the virtual prototype for operational stability and ride comfort simulation test can be accomplished on computer before the sample vehicle is made. Thereby it can shorten the production cycle, reduce cost and has wide application prospects.Being based on the development status of an UTV, this paper used virtual prototype technology, did the vehi-cle handling stability analysis of full vehicle model with a rigid-flexible coupled suspension by using ADAMS/CAR, and then evaluated result of the simulation.In this paper, firstly, using the UTV parts drawings and reference vehicle given by one manufacturer,the 3D vehicle model is drew, essential parameters for building the front or rear suspension and vehicle virtual prototype model are extracted.Using Hypermesh and Motionview software set up the flexible body of the cross arm up and down in front or rear suspension.After that did the modal analysis.The results show that the frequency are larger than the frequency of the vehicle body, and resonate with the body won’t happen,then MNF file combined with ADAMS software is outputted,preparing for the establishment of rigid-flexible coupling model of suspension.Secondly, the front and rear suspension model of multi-rigid-body and the Rigid-flexible coupled front and rear suspension simulation model are established,basing on the modeling parameters.The comparative simulation analysis of the suspension is done between the multi-rigid-body model and rigid-flexible coupling model. The curve that wheel toe in, camber Angle,kingpin caster angle,kingpin inclination angle change with the wheel movement are outputted. The analysis results show that wheel alignment parameters of the two front and rear suspension model are in agreement with the relevant provisions of the Handbook of Automotive Engineering. The graphs also show that the flexible deformation of the structure have certain impact to wheel alignment parameters. Flexible body is closer to the reality, simu-lation and analysis of its results is more accurately.Using the rigid-flexible coupling full-vehicle model can get more accurate handling stability.It laid a foundation for the follow up simula-tion tests of vehicle virtual prototype model with the rigid flexible coupling suspension.Finally, the subsystems of steering subsystem model, car model, tire model, braking model and the dynamic model is established, combined with the front and rear rigid flex -ible coupling suspension subsystem model, adjusted the hard point parameters and com connection well,and then assembled into a virtual prototype model of rigid-flexible coupled sus-pension. The vehicle handling stability performance is simulated, and there are comprehe-nsive scores of the steady static circular tests, the steering return tests and the pylon courses lalom tests, in order to determine if the all terrain vehicle handling stability performs well. The result shows that the steady static circular performance gets a score of 75.51,at the same time,83.85 is for steering return performance and 89.03 is for hunting characteristic. The results meet the requirements of national standard, indicating that the vehicle handling and stability can meet the requirement for the vehicle in automotive industry,but steady static circular performance get a relatively low score,it needs to be improved.This results provide a direction for the enterprise to improve the performance of its products.The results show that:the handling stability performance of this UTV can meet the national standards,but some improvements on the structure and configuration are still nee-ded.The lack of stabilizer bar is one of the major factors affecting the handling stability, we can also add electronic control system to improve the handling stability, and then impr-ove the capability of whole car.