Analysis of Dynamic Stability of Nonlinear Suspension concerning Slowly Varying Sprung Mass

Abstract EN

In this paper, the stability of vehicle concerning the slow-varying sprung mass is analyzed based on two degrees of freedom quarter-car model.

A mathematical model of vehicle is established, the nonlinear vibration caused by sprung mass vibration is solved, and frequency curve is obtained.

The characteristics of a stable solution and the parameters affecting the stability are analyzed.

The numeric solution shows that a slow-varying sprung mass is equivalent to adding a negative damping coefficient to the suspension system, making the effective damping coefficient change from negative to positive.

Such changing parameters lead to Hopf bifurcation and a shrinking limit cycle.

The simulation results indicate the existence of static as well as dynamic bifurcation and the result is a change in the final stable vibration of the suspension.

Even the tiny vibration of the sprung mass will lead to amplitude mutation, leading to the sprung mass instability.