Simulation Study On Damping Characteristics Of Double Tube Shock Absorber

Double-tube hydraulic shock absorbers are widely used damping accessories in our automotive industry.They are an important part of the vehicle suspension system and can greatly improve the ride comfort and safety of the vehicle during driving.This paper studies the vibration demand of the twin tube hydraulic shock absorber in the process of vehicle movement,and uses the external characteristic curve of the twin tube shock absorber to reverse the technology to master the technology of matching the suspension system.The mainly focuses on the reverse calculation of the twin tube shock absorber valve system parameters.The mathematical model and 3D solid model of the twin tube shock absorber are combined with computer simulation technology CAD/CAE.After fluid-solid coupling simulation,the internal valve system structure parameters of the twin tube shock absorber are continuously optimized.Finally,the external characteristic curve of the matching suspension system is obtained.The main contents are as follows.The basic structure and working principle of twin tube shock absorber are analyzed comprehensively.The shape of the external characteristic curve of the twin tube shock absorber,the"inflection point"CK₁,CK₂",and the size of the safety ratio are clarified,and with the parameters of the final fluid-solid coupling simulation.According to the analytical calculation theory of elasticity,the structure and stress characteristics of different types of throttle discs of twin tube shock absorbers are studied in detail,and the mathematical model of the deformation of the throttle discs and the magnitude of the stress is established.Accurately obtain the magnitude of the deformation of the valve plate in any direction and the value of the"Great Wall coefficient"of the throttle valve plate.According to the internal structure of the twin tube shock absorber,the internal working conditions of the twin tube shock absorber at different speeds:slow,medium,and fast are analyzed in detail.The mathematical model of the flow field inside the twin tube shock absorber is constructed,and the initial throttle valve opening speed point,the maximum throttle valve opening speed point and the speed-related damping force segmentation function of the twin tube shock absorber recovery stroke are obtained.According to the solid model of the twin tube shock absorber,the flow field model is drawn,and the simulation analysis is carried out by means of two-way interaction fluid-solid coupling.After CFD-POST processing the data,the F-V velocity characteristic curve and the F-S indicator diagram curve are obtained.Optimize the internal parameters of the twin tube shock absorber according to the external characteristic curve.The simulation results show that it is basically consistent with our theoretical calculation results on the whole,and meets the requirements of the external characteristics of the shock absorber.