【作者】 方明霞； 冯奇；

【Author】 Fang Mingxia Feng Qi Dynamic and Control Institute of Tongji University,Shanghai 200092

【机构】 同济大学动力学与控制研究所；

【摘要】 本文首先建立了悬架系统的数学模型。由于悬架系统中具有众多的橡胶减振元件,其应力—应变循环具有变刚度变阻尼的非光滑、强非线性特性,恢复力表现出与变形历史有关的迟滞性。为了建立其数学模型,论文将恢复力分解成非迟滞非线性弹性恢复力和纯迟滞非线性阻尼力两部分,并用多项式和类椭圆函数分别进行模拟,用所建模型重构恢复力—位移迟滞回线,与试验结果吻合较好。然后利用系统动力学和随机振动理论,将汽车简化为四自由度模型,建立考虑悬架迟滞非线性特性的整车系统在路面随机激励下的非线性动力学方程。最后用Monto Carlo法模拟路面随机激励谱,在时域内对整车非线性系统振动特性进行仿真,并与传统的考虑线性悬架系统的整车动力学特性进行对比,以研究悬架迟滞非线性特性对汽车平顺性的影响。更多还原

【Abstract】 First, the mathematic model of suspension system was established. For there are many rubber components in suspension system, its stress-strain curve has non-smooth and strong nonlinear properties, and hysteretic characteristics with distortion history exist in restoring force. In order to establish its mathematical model, restoring force was separated into two parts: elastic one and damping one, and different functions were used to simulate them. The force vs. displacement hysteretic loop was reconstructed using obtained model, it fit to the experimental data well. Then, utilizing theoretics of system dynamics and random vibration, 4 DOFs entire-car nonlinear dynamic equation considering suspension hysteretic nonlinear properties was set up, which excited by road random load. At last, using Monto Carlo method to simulate road exciting spectrum, the kinematic differential equation of entire-car system was simulated in time domain. The result of simulation was also compared with entire–car linear system, so the influence of automobile ride comfort by suspension hysteretic nonlinear properties were obtained.更多还原