Dynamic Response Analysis Of Light Truck Nonlinear Under The Road Deceleration Strip Excitation

Dynamic problems in the development of national economy and science and technology have a very wide range of applications, and the most frequently encountered problem is structural dynamics. There are two types of research object of Structural dynamics problem, one kind is mechanical structures working under the motion state, they both bear inertia influence, and dynamic loading of surrounding media or institutions under, another kind is engineering structure under dynamic loading.In recent years, the penetration of vehicles is higher and higher, and with the improvement of production technology, the performances of the vehicles make astounding advances. At the same time, the high frequency of traffic accidents caused by over speeding driving more and more focus of attention on traffic safety. Controlling vehicle speed gradually aroused the attention of people. Road deceleration strips, as a kind of commonly used highway mandatory speed facilities came into being, and plays an irreplaceable role in avoiding the occurrence of traffic accidents and guaranteeing traffic safety. When vehicles speeding through deceleration strips, sudden severe vibration will bring the passengers discomfort of vibration and noise, and also can bring the psychological scruple of damaging vehicle parts to drivers. These feelings will force the driver to slow down.Vibration energy transfers to the suspension system, due to the widespread nonlinear factor of the automobile suspension system under certain load, incentives and frequency conditions are likely to lead vehicles to suspension complex nonlinear dynamics behavior such as chaotic vibration. So the study on the dynamic response of automobile suspension system under the condition can provide the basis for automobile production and daily traffic with practical significance.To this end, this paper respectively, a half-vehicle nonlinear suspension model with6DOFs is established according to a certain model parameters of light trucks. A nonlinear hysteresis damping model, tire speed-ground contact function model, and two kinds of common strips models are established. With the Lagrange method the system vibration equation is established, and each degree of freedom vibration system is decoupled. Using the Newmark method to calculate the mechanical response of the suspension model system speeding through the two strips. Through the analysis of the nonlinear dynamic response of the system form, the nonlinear dynamic response form of the system is gotten.In order to ensure passengers’ comfortable feeling, the light truck driver should try to control within20km/h speed passing simple rubber deceleration strips.In less than42km/h speed, bridge vertical vibration is mainly in the period-doubling vibration form. Speed continues to increase; vibration form turns to quasi-periodic vibration.When the speed is less than50.5km/h, vertical vibration of the cab is mainly in quasi-periodic vibration. With a increase in the speed, when the speed is in50.5km/h-58.5km/h range, bridge longitudinal vibration of the cab is main period-doubling vibration. When the speed increases up to58.5km/h, vibration form turns to chaos vibration mode.