Dynamic Characteristic Analysis Of Vehicles With Considering The Nonlinearity Of Rubber Bearings

How to improve the vehicle ride comfort, as one of the main technical performances ofautomobile, is always a hot issue for engineers. With the requirement of ride comfort gettinghigher, there are more and more nonlinear damping elements like rubber bearings used in everysystem of vehicles. And those rubber bearings are used to mitigate the pavement impact anddamp the vehicle body's vibration resulting from road roughness. Therefore, study about thedynamic characteristics of vehicles containing nonlinear damping system is much useful fortheory and engineering.Taking rubber bearings with hysteretic nonlinearity as the study subject, this paper builds adynamic mathematics model for rubber bearings under the condition of random excitation,which researches on the influence of the rubber bearings' hysteretic nonlinearity on dynamiccharacteristics of the vehicle. The main contents of this dissertation are listed as follows:Firstly, based on the dynamic characteristic test analysis of rubber bearings, a mathematicsmodel for rubber bearings under random excitation is built. In this model, the hystereticrestoring force under random excitation includes two parts, namely non-hysteretic non-linearelastic restoring force and hysteretic non-linear damping force. Meanwhile, the force is not onlyrelevant to the displacement and the speed but also relevant to the mean value and the standarddeviation of the random displacement. The force-displacement and force-time relationships arereconstructed by the model built in this paper under the conditions of different samplingsections with same preloading and same displacement amplitude and of different workingconditions with different preloading and different displacement amplitude. And the result showsthat the simulation and test matches with each other well.After implantation of the mathematical model, the eleven-degree-of-freedom vibrantmodel is built for full vehicle dynamic model. With random road excitation as input excitation,analysis in time domain for the influence of rubber bearings on the dynamic model is done. Thesimulation and analysis results show that the rubber bearings are very useful for the ridecomfort. So, on vehicle ride-ability research, it is very necessary to consider the influence ofrubber bearings on the whole vehicle.