| Based on the theory of Multi-Body System Dynamics, multi-body system dynamics models of front and rear suspensions model are built in the Mechanical System Simulation software, ADAMS/CAR, and dynamic simulation off front and rear suspensions system dynamics were performed and the modifying strategies were put forward; the full vehicle model including engine, steering system, front and rear tire etc based on the analysis of front and rear suspension. The experiment validation were made focus on the release of steering, impulse input, step input and constant radius steering. At last we discussed the factors which of them influence the handling and stability of full vehicle. The whole article include five chapters:In chapter one, we reviewed on the growing history, status quo and future trend of vehicle system dynamic modeling. A brief described the research content and significance. The system dynamic model are coming through from simple to complication, from linear to non-linear, from few parts to complicated assembly, the general multi-body codes were gradually used. Such as ADAMS,MEDYNA,NEWEUL,DADS,AUTOSIM and SIMPACK etc. expound the implication of dynamic simulation in suspension and full vehicle development combining with the development project of a updating SUV.In chapter two, introduced the research method----the theory of multi-body system dynamic. the thorough introduction to the modules and theory of ADAMS, one of the most popular multi-body system dynamics software packages. Chapter Three is divided into two parts. Expound the application of ADAMS/CAR in front and rear suspension development respectively. Suspension system is the mainly assembly of vehicle, influence the handling stability and ride comfort greatly. The traditional design methods are experiential design, mathematic calculation and geometrical construct etc, the design can satisfy the requirement but the precision and efficiency is low, can't keep up the upspeed design requirement, new design method must be adapted in order to shorten the development period and cut cost. ADAMS/CAR module has the professional kinematics and dynamic analysis template for suspension, all kinds of suspension can constructed conveniently and more than thirty kinds of parameters curves about the suspension can be made rapidly. The kinematics and dynamic analysis arm at the front and rear suspension system of a updating SUV, the motion law was uncovered respectively. The front suspension is double wishbone independent suspension, the anti-dive and anti-lift performance is bad and the wheel rate curve and roll stiffness curve descend rapidly along with the wheel travel up, in the guide of modify as few as better of the parts, made the low control arm front point connected to the body 20mm down, the results indicate the wheel rate curve and roll stiffness curve descend trend is slowed, the dive and lift quantity minished a lot. The key parameters such as wheel rate and wheel center displacement is calculated,the optimization analysis of key points was performed at the optimization arm of wheel center longitude and lateral displacement, the modifying strategies were put forward.In chapter four the full car handling stability was performed. The full vehicle simulation mode is built including front and rear suspension, anti-roll bar, steering system, damper, engine, driver room and body, tires etc based on the suspension analysis in former chapter, many handling stability simulation analysis were performed and validated with the experimental results, and elementary discussion about the main influence factors to the handling stability was carried out. In order to evaluate the handling stability the object group have carried out the pylon course slalom test, steering wheel angle step input test, steering wheel angle pulse input test, returnability test, steering efforts test, steady static circular test according to the test methods of handling stability in GB/T6323—1994 looking upon the vehicle as a open loop system. Educed the time dom...
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