| Suspension system is the important part of Running Department, its quality and performance directly affect the riding comfortableness, the running security and the steering stability. This thesis choosing certain type automobile suspension, firstly discusses the performance of suspension from smoothness and amplitude-frequency characteristic, and then analyzes the temperature rising of shock absorber and the valve piece deformation ,which have important impact to the performance of suspension system, lastly, based on the above analysis, it takes the optimization design for the whole suspension parameters. This thesis provides the improvement method and mentality for the riding comfortableness and the running security.The main achievements are as follows:1,Through the smoothness analysis, we establish the relationship between weighting acceleration root mean square value and intrinsic frequency of wheel,intrinsic frequency of bodywork,damping coefficient of car body,mass ratio,relative damping coefficient, and provide the datum for understanding the influence of above factors to smoothness.2,For security and smoothness, there are four improving projects: when the other parameters stay the same, (1)set the wheel stiffness to 694500N/m; (2)set the suspension stiffness to 111000N/m; (3)set the suspension mass to 3100 kg; (4)control the running speed under 80.28 km /h.3,The temperature of shock absorber increases along with the operating time increase by the non-linear way, and it has a balance temperature. The balance temperature is sensitive to the convection coefficient, surface area of shock absorber, wheel stiffness, non-suspension mass, and running speed.4,The relations between restoration valve piece deflection the damping force, the compression valve piece deflection and the damping force are expressed by the equations below:(1)wf=-0．0005+4．788×10-5Ff-2．204×10-10Ff2;(2)wy=0．003+9．694×10-5Fy-5．466×10-9Fy2+1．594×10-13Fy3。5,The best parameters-combination of this suspension is: non-suspension mass m1 =360kg, suspension mass m2 =3000kg, wheel stiffness k1=1650000 N/m, suspension stiffness k2=1 80000 N/m, damping coefficient of shock absorber c=10050Ns/m。...
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