参数慢变磁流变非线性悬架系统主共振研究

Main resonance analysis for a MR suspension system with slowly varying parameters

针对磁流变阻尼器随工作温度变化导致阻尼力发生改变,进而降低磁流变悬架系统性能的问题,基于传热学方程和参数慢变非线性振动理论研究温度变化对磁流变非线性悬架系统的主共振动力学行为的影响。根据传热学理论建立磁流变阻尼器工作区域能量微分方程,用数值方法求出温度变化规律,用改进的Bingham模型计算磁流变阻尼力;建立慢变参数磁流变非线性悬架系统动力学方程,利用平均法求解主共振激励下的悬架动行程的稳态幅值响应。研究表明:随着运行时间增加,磁流变阻尼器的温度逐渐升高,导致磁流变阻尼力大幅降低,悬架动行程稳态振幅及其变化量越大,从而使得悬架系统的性能偏离设计目标。

The output damping force of a magneto-rheological（ MR） damper is reduced with increase in working temperature. As a result,the performance of a MR suspension system is degraded. On the basis of the theory of heat transfer and nonlinear vibration,the main resonance of a MR suspension dynamic system with slowly varying parameters was analyzed here. The energy differential equations at the working area of the MR damper were established and solved with the numerical method. The modified Bingham model was applied to calculate the output damping force of the MR damper. The nonlinear dynamic equation of the MR suspension system with slowly varying parameters was formulated. The steady amplitude response of the MR suspension system under the excitation of main resonance was solved with the averaging method. The calculated results showed that the working temperature rises with increase in running time of the MR damper,consequently,the output damping force of the MR damper decreases significantly and the vibration amplitude variation of the suspension system increases,the performance of the MR suspension system is degraded.