Simulation Of Dynamic Characteristics Of Hydraulic Shock Absorber By Fluid-Solid Interaction (FSI)

Two-tube hydraulic shock absorbers are a kind of widely used absorbers in Cars. It is very meaningful to the development of shock absorber technology to improve the design methods and provide more accurate forecast of its performance characteristics. Its performance characteristics may be affected by many nonlinear factors such as fluid-solid coupling, making the design and the analysis of the shock absorber very difficult. Traditional design method is not only a long cycle, but also hard to obtain the optimal damper characteristics. With the continuous development of computer technology, CAD design of the shock absorber becomes the trend of shock absorber design.In this paper, a commonly used type of two-tube hydraulic shock absorbers was studied. By analyzing the structure and operating principle of the shock absorber valve system, a dynamic model of rebuilt valve fluid-solid coupling was built, and the model scale and overall computing time was sharply reduced by adding axis constraints to the contacts between stacking valve groups. Meanwhile, the time chart of valves, deduced by analyzing the deformation of the stacking valve group and the flow field characteristics near the valve group, validated the model. The method, to some extent, could make the designed parameter of shock absorber less depend on the experiment. In the last place, the physical shock absorber was tested on bench based on national standards, and the chart of responding technical characteristic was gained and the effectiveness of the follow-up model was validated.A dynamic model of fluid-solid coupling of two-tube hydraulic shock absorber was built in this paper, and the model was divided into two parts including rehabilitation and compression according to the working process of shock absorber. The grid quality of the oil through-hole and the coupling regional model were ensured by effective meshing technology. Solution convergence was improved effectively due to means of an empty load step and non-dimensional technology. Subsequently, some analysis related to the characteristics of a continuous steady-state behavior of the three–dimensional closed oil circuit of shock absorber were done. By converting the pressure difference between valve systems working in different strokes into absolute pressure, the speed damping characteristics of the model was obtained, and then it was compared with the experimental data in order to analyze the accuracy and shortcomings of the model. The established dynamic model in this paper can offer technical reference to the shock absorber related product design.