In this paper, modeling impact dynamics of a piston and its cylinder body in a hydraulic cylinder is investigated. The studied system consists of two identical hydraulic cylinders controlled by a pressure sequence valve. The impact is assumed as a linear one dimensional and purely translational viscoelastic impact of rigid bodies. Four impact models, the Kelvin-Voigt, the Maxwell, the standard-solid, and the Hunt-Crossley, are considered. Measurements of the transient variations of the cylinders operating pressures and both pistons strokes, at different loading conditions, are conducted. A comprehensive dynamic model of the studied system, considering the four models, is deduced. The Kelvin-Voigt model produced tensile forces by the end of the contact period and it resulted in discontinuities in the contact force during its steady state period. Both results are physically impossible in rigid bodies impacting. In the Maxwell model, large amount of discontinuities appeared in the contact force, which causes the piston to make an infinite number of rebounds during the contact period. In the standard-solid model, the discontinuities in the contact force were found to be much less than those of the Maxwell model. As a result, when the impact occurs, the cylinder pressure gets an overshoot accompanied with large oscillations when the Maxwell model is applied, however, these oscillations do not approximately appear when the standard-solid model is applied. The simulation results showed also that the Hunt-Crossley nonlinear model presented very high penetration depth, which is certainly unrealistic in rigid bodies impacting. The validation of the proposed dynamic models showed that the standard-solid is the most suitable model that may represent the impact in the studied cylinders.

本文研究了液压缸中活塞及其缸体的冲击动力学建模。研究的系统由两个相同的液压缸组成，这些液压缸由压力顺序阀控制。该冲击被假定为刚体的线性一维和纯平移粘弹性冲击。考虑了四个冲击模型，开尔文-沃格特，麦克斯韦，标准固体和亨特·克罗斯利。在不同的负载条件下，对气缸工作压力和两个活塞冲程的瞬态变化进行了测量。推导了考虑这四个模型的研究系统的综合动力学模型。Kelvin-Voigt模型在接触期结束时产生了拉力，并且在稳态期间导致了接触力的不连续性。在刚体撞击中，这两种结果在物理上都是不可能的。在麦克斯韦模型中，接触力中出现大量不连续，这导致活塞在接触期间产生无限数量的回弹。在标准固体模型中，发现接触力的不连续性远小于麦克斯韦模型的不连续性。结果，当发生冲击时，使用麦克斯韦模型时，气缸压力会出现超调并伴有大的振荡，但是，当应用标准实体模型时，这些振荡几乎不会出现。仿真结果还表明，Hunt-Crossley非线性模型具有很高的穿透深度，这在刚体撞击中肯定是不现实的。