工程车辆油气悬架参数化建模与幅频特性分析

Parametric Modeling and Amplitude Frequency Characteristics Analysis for Hydro-pneumatic Suspension of Engineering Vehicle

为了测试某工程车辆油气悬架系统螺旋弹簧和油气弹簧的综合刚度及分析车身幅频特性的主要影响因素,设计了减震器试验台,根据质量集中原则和牛顿定律,建立了基于实验的1/4油气弹簧悬架非线性振动模型。运用泰勒展开和谐波平衡法相结合的方法将系统方程转化为非线性代数方程组,求得了系统近似稳态解,其结果与龙格-库塔法求解较为接近,在此基础上分析了影响车身幅频特性的主要因素。结果表明,氮气初始气压、路面激励幅值、质量比和轮胎刚度的变化对车身共振频率的影响较小,但对车身振幅有较为明显的影响。具体表现为氮气初始气压、路面激励幅值和质量比的增大使车身振幅加大,轮胎刚度的增大不仅使车身振幅增大,还增加了车身达到稳态振动的时间。

A shock absorber test instrument is designed in order to test the comprehensive stiffness of the helical spring and the hydro-pneumatic spring of the hydro-pneumatic suspension of engineering vehicles,and to analyze the main factors that influence the body amplitude frequency characteristics.Firstly,one quarter of the hydro-pneumatic spring nonlinear vibration model is established according to the mass con-centration principle and Newton′s second law.Then,the system equation is transformed into nonlinear algebraic equations by the Taylor expansion and the harmonic balance method,and the system steady-state solution is obtained.The results show that the solution is close to the one obtained using the Runge-kutta method.On this basis,the main influence of the amplitude-frequency characteristics of the car body is analyzed.The results show that increasing initial nitrogen pressure,road excitation amplitude,and mass ratio has little effect on body resonance frequencies,but serves to increase body amplitude.At the same time,the tire stiffness increases both the body amplitude and the time of the body to steady-state vibration.