悬架系统非线性减振器阻尼值变化系数对整车振动影响的研究
Research on Effect of Variation Coefficient of Nonlinear Suspension System of Shock Absorber Damping Values on Vehicle Vibration

以MATLAB/SIMULINK为研究平台，搭建了包括车身垂直，俯仰和侧倾的七自由度非线性整车分析模型，讨论了汽车在随机路面谱激励下，非线性悬架系统对于整车振动的影响，并通过实车试验验证了所分析结果的正确性。论文详细分析了悬架阻尼非线性特性对车身总加权振动加速度均方根值的影响规律，研究结果表明：不同的复原行程阻尼值变化系数nr和压缩行程阻尼值变化系数nc会不同程度的影响整车的振动，较小的变化系数会增大车身总加权振动加速度均方根值，而过大的变化系数对于整车平顺性并无较大改善。研究结果还表明变化系数相同的双向阻尼值变化系数nrc和ncr对整车振动影响很小。所开展的阻尼非线性对车身加权加速度振动响应影响的研究规律研究，考虑了对人体较为敏感的水平振动的影响，对于改善整车平顺性的悬架系统设计有一定的指导作用。
A seven degree of freedom (7-DOF) nonlinear vehicle model which included vertical, pitch and roll motions were built in MATLAB/SIMULINK, the nonlinear effects of the shock absorber on the vehicle under the random excitation was discussed. The vehicle test results proved that the analysis were correct. Then the influences of the nonlinear shock absorber damping on the vehicle total weighted RMS vibration acceleration was studied. The results show that different rebound stroke damping variation coefficient nr and compression stroke damping variation coefficient nc will affect vehicle vibration on varying degrees, and small variation coefficient will increase the total weighted RMS vibration acceleration, while large variation coefficient do not improve the ride comfort. At the same time, the results show that the same variation coefficients of the double-side damping value nrc and ncr have little effect on the vehicle vibration. This paper considered the sensitive direction to human body, it provides a guidance to design a good ride comfort vehicle suspension