Influence Of Temperature Effect On Dynamics Of Vehicle Shimmy System With Clearance In Movement Pair Of Steering Box

Automobile front wheel shimmy is a mixable movement, which is made up ofthe roll movement of front axle around longitudinal axis and the yaw movement offront wheel around king pin. The Snake Motion of the car would be caused bysevere vehicle shimmy with serious shaking of steering wheel and body. Moreover,it has serious negative effects for increasing the tire wear, magnifying the dynamicload of steering mechanism, shortening the service life of relevant parts. Vehicleshimmy also have serious adverse impacts on the car power dynamic, fuel economy,handling stability, riding comfort and safety.Many researchers have deep researched on the wheel shimmy mechanism,typically, the mechanical characteristic of tire, the steering wheel alignmentparameters and the Steering system structure parameters, and made a lot ofimportant achievements. Based on previous research results in our group，whichconsidering assemble clearance and random clearance，the clearance in movementpair of steering box which includes temperature parameter was investigated. Theperformance of shimmy was discussed under different temperature and speed.Taking vast region and different temperature of our country into account, thedynamical behavior of clearance leading vehicle shimmy system which is underuncertain temperature conditions was discussed. Basing on the Heat deflectiontheory of thermoelasticity, this paper analyses the thermal deformation mechanismof steering movement pair under uncertain temperature conditions. Furthermore, aclearance leading vehicle shimmy dynamical system was established, which wasbased on the temperature. Through phase plane method, Poincaé mapping method,power spectrum and bifurcation diagram, this paper analyses the Stability andBifurcation of vehicle shimmy system to explain the significance of temperaturefluctuation. In addition, employing point mapping method, the global dynamicalbehavior of the system was analyzed. The fit tolerance of movement pair ofclearance was discussed， which provides a theoretical guidance for effectiveattenuation of wheel shimmy.