Research On Vehicle Ride Comfort Based On Mechanical Properties Of Rubber Bushing

Vehicle ride comfort is one of the important performances of automobiles.With the improvement of people’s consumption level,increasingly fierce competition of car companies,people put higher requirements for vehicle ride comfort.Due to their high elastic energy and damping,rubber bushings are widely used in vehicle suspension systems,which play a role in reducing vibration and noise and making up for manufacturing tolerances.The development and research of ride comfort are mostly based on partial frequency design which is determined by the positioning parameters、the guiding structure and the spring,etc.However,there are few studies on the mechanical properties of the rubber bushing between components for ride comfort.So,the influence of the mechanical properties of rubber bushing on the ride comfort is an important part of the research of ride comfort.Through the MTS uniaxial test rig、the ABD suspension K&C test rig and the ride objective test equipment of the China Automotive Technology and Research Center Co.,Ltd.,Rubber bushings、suspension K&C and ride comfort tests of the test vehicle SUV were carried out.This paper analyzed the tests’ data,and interpreted the objective data with the subjective evaluation of the tests’ vehicle.Through the tests’ data of the rubber bushing,this paper compared several models describing the dynamic mechanical properties of the rubber bushing.Selected the Frequency-Dependent model to describe the frequency dependence of the rubber bushing.Selected the Bouc-Wen model to describe the amplitude dependence of the rubber bushing.Based on the classical seven-degree-of-freedom vibration model,a seven-degree-offreedom vibration model including rubber bushing was established.Combining the road roughness and ride evaluation index,this paper constructed a system framework that describes ride comfort and established two mathematical models through MATLAB.Through comparing the natural frequency of the vehicle body、the natural frequency of the wheel,and the dynamic deflection of the suspension spring,this paper verified the accuracy of the seven-degree-of-freedom vibration model including the mechanical properties of the rubber bushing.In this paper,a rubber bushing model with dynamic mechanical properties was built by the Adams/Ride and verified by frequency simulation.The multi-body dynamics vehicle model of the experimental vehicle SUV was established by Adams/Car.It was carried out the ride comfort simulation to verifying the accuracy of a multi-body dynamics vehicle model with dynamic mechanical properties of rubber bushings.Through changing the dynamic stiffness of rubber bushing located at the rear mounting point of the front suspension lower swing arm,this paper studied the effect of the dynamic stiffness of the rubber bushing on the ride comfort.The results showed that rubber bushing located at the rear mounting point of the front suspension lower swing arm had a greater impact on longitudinal vibration of the vehicleThe seven-degree-of-freedom vibration mathematical model and multi-body dynamics model including the dynamic mechanical properties of the rubber bushings established in this paper can provide a theoretical basis for the exploitation of the chassis of the vehicle,provide reference for the vehicle chassis adjustment in the later stage of the project,which reduce the tuning and exploitation cycle.