汽车动力总成非线性能量阱参数设计方法

Parameter Design Method of Nonlinear Energy Sink for Automobile Powertrain

为控制汽车动力总成的垂向振动,建立了动力总成-非线性能量阱(nonlinear energy sink,NES)二自由度振动模型,考虑动力总成激励力主要为简谐激励和冲击激励。在动力总成简谐激励下,利用复变量-平均法推导了系统慢变方程,得到稳态响应方程,并判断解的稳定性。以平均能量耗散率最大为优化目标,对NES刚度进行优化,优化后的NES减振效果得到明显改善。利用时程曲线、相轨迹和Poincaré映射对系统响应机制进行分析,得到系统响应机制对减振效果的影响规律,给出NES阻尼的优化原则。最后,在动力总成冲击激励下,计算分析了系统各参数对减振性能的影响规律,给出NES刚度和阻尼的优化方法,结果表明优化后的NES能够有效地抑制动力总成在冲击激励下的振动。

In order to control the vertical vibration of the automobile powertrain,a powertrain-nonlinear energy sink(NES)two-degree-of-freedom vibration model was established,considering that the powertrain excitation force was mainly harmonic excitation and impact excitation.Under the harmonic excitation of the powertrain,the slow-varying equation of the system was derived using the complex-averaging method,the steady-state response equation was obtained,and the stability of the solution was judged.Taking the maximum average energy dissipation rate as the optimization goal,the NES stiffness was optimized,and the optimized NES vibration reduction effect is significantly improved.The time history curve,phase trajectory and Poincarémapping were used to analyze the system response mechanism,and the influence law of the system response mechanism on the vibration reduction effect was obtained,and the optimization principle of NES damping was given.Finally,under the shock excitation of the powertrain,the influence of the system parameters on the vibration reduction performance was calculated and analyzed,and the optimization method of NES stiffness and damping was given.The results show that the optimized NES can effectively suppress the shock excitation of the powertrain.