摘要
运用非线性动力学理论和Matlab 6 .1对分别采用轮胎非线性模型和线性模型的汽车悬架的运动特性进行比较 ,结果表明轮胎的非线性特性对汽车悬架的动力学特性有很大影响 ,在高速运动。
The nonlinearity of tyre is an important element in the nonlinearities of the whole vehicle suspension system. However, researches before regard the tyre as a combination of a linear spring and linear damp. So, it should be studied that whether the tyre should be taken as a nonlinear tyre. This problem is solved in this paper. Firstly, the nonlinear model of the tyre is adopted. This model is worked out in a reference paper. In that paper, the author does a great deal of experiments to get the model. They make sure that the tyre can be modeled as a combination of a nonlinear spring and linear damp. This model is good enough to show the kinematic features of a tyre. As this model is adopted, the suspension of a car turns into a nonlinear system. The one fourth car model is used for the study. Though it is obvious that other nonlinear elements will influence the feature of the suspension, the nonlinearity of the tyre is the only element dealt with here. Secondly, after setting up the nonlinear suspension model, the kinematic equation of the model is studied. Then it is changed into a matrix style. That the rank of matrix is 4, makes it difficult to give an analytic value of the stability of the system. Thirdly, the way to express the power of the road surface is studied. According to the usual habit, the power is taken as a sine power. As we all know, a sine power is good enough in a kinetic computation. After that, the model is simulated with Simulink, a powerful tool in Matlab. With this simulation, we can get the response of the model suspension to a road surface easily. To make a comparison, both the nonlinear model and the linear model are all simulated. By changing the frequency of the input power, different responses are got. Relations between the response and the input just reveal the features of the model suspension. By comparing the features of the nonlinear model suspension with the linear suspension, we get some results. 1) The linear model suspension is sensible of the frequency of the input power, which means that by changing of the frequency, the corresponding swing will change much. As to the nonlinear model suspension, it is not so. 2) When the frequency reaches some value, the corresponding swing of the linear model suspension is in normal status, while the corresponding swing of nonlinear model suspension is already unlimited. 3) The swing of the linear model suspension is symmetrical about the point of balance. To the nonlinear model suspension, it is on the contrary. Also, other differences between linear model suspension and the nonlinear one are described here. We draw out such a conclusion from those comparisons: the nonlinear feature of tyre has great influence on the suspension of a car. As so, to reflect the kinetic features of the suspension well, it is necessary to simulate the suspension with a nonlinear tyre model. However, this is just a primary study of the influence of the nonlinear tyre. When affecting by the nonlinear tyre and other nonlinear elements, what the status of the suspension will be, is worth studying. More researches should be done to analyze the influences of the nonlinear tyre to know the idiographic result.
出处
《机械强度》
CAS
CSCD
北大核心
2002年第3期345-348,共4页
Journal of Mechanical Strength
基金
天津市自然科学基金资助项目 (0 0 360 371 1 )~~
关键词
汽车悬架
非线性
轮胎
模拟
振动
Automotive suspension
Nonlinear
Tyre
Simulate
Vibration
