汽车平顺性建模及其仿真研究

Modeling and Simulation of Automobile Ride

通过分析汽车振动源和人体对振动的反应，用模态综合技术，建立了十三自由度人－椅－车系统的动力学模型，运用随机振动理论，给出了振动形态、传递函数、悬架动挠度、车轮动载荷、座椅加速度等参量的计算方法，开发了一套“汽车平顺性仿真软件”并利用已有的汽车数据，对汽车行驶时的振动特性进行了仿真，得到了重要结论：发动机与轮胎刚度、阻尼，后桥阻尼对驾驶员座椅处的振动影响不大；驾驶员座椅的垂直刚度增加很大时，对垂直方向振动响应比较大；前桥刚度、阻尼对驾驶员座椅处的振动影响较大；前轮胎刚度对前桥振动影响较大，前轮胎刚度增加，则振动加强；后桥刚度对汽车平顺性有一定影响，后桥刚度减小，则座椅处垂直加速度减小．

From the analysis of automobile vibration sources and the human responses to vibration, a mechanic model of man-chair-vehicle system with 13 degrees of freedom is built by vibration pattern analyzing technology. Using the random vibration theory, the calculating methods are developed for parameters, including vibration pattern, transfer function, wheel transient load, and acceleration of seat, automobile ride quality simulation software is developed. With available data of motor, the simulation calculating results about vibration character istics are given, and important conclusions drawn are as follows: the stiffness and damping of the generator and wheel tire and the damping of back-axis have not much effect on the vibration of the seat; Vertical stiffness of driver's seat has much effect on the vibration as it gets larger; The stiffness and damping of fore axis have much effect on the vibration of driver seat. The stiffness of the fore tires has much effect on the vibration of the fore axis. The vibration increases with the stiffness of fore tire increasing, The stiffness of back axis has some effect on the automobile ride quality. As the stiffness of back axis decreaseds, the acceleration of the driver′s seat decreases. With this simulation software, automobile ride quality can be predicted or evaluated.