Abstract: A secondary vertical multi-functional damper(hereinafter referred to as multi-functional damper) is proposed, which can reduce the number of suspension components, save manufacturing and maintenance costs, and make the vehicle have higher curve safety. The multi-functional damper can provide the function of vertical vibration reduction, and achieve the effect of anti rolling. According to the different motion states of vehicle vertical vibration and roll motion, it has the function of vertical vibration reduction and roll resistance through the connected structure and damping valve system. The mathematical model of the multi-functional damper is established, compared with the experimental results, it is verified that the accuracy of the damper model is better. Then, the vehicle dynamics model is co-simulated to analyze the influence of the multi-functional damper on the dynamic performance of the vehicle system. The simulation results show that the multi-functional damper can provide enough anti rolling stiffness instead of anti rolling torsion bar. Compared with the anti rolling stiffness of the traditional anti rolling torsion bar, the multi-functional damper can achieve variable stiffness, when the roll angle increases, it provides greater anti roll stiffness and make the vehicle have higher safety.

Key words: secondary vertical multi-functional damper, vertical vibration, anti rolling, nonlinearity stiffness