Abstract:
This thesis presents the comparative study of a quarter car passive suspension model which
consists of a two-degree of freedom with a linear and a non-linear suspension component
such as: spring, damper and tire. The ride quality including comfort and road holding is the
primary factor that is targeted in the study of an effective suspension system. The
mathematical model of quarter car suspension is derived, and the dynamic results are
evaluated in terms of the sprung and unsprung mass displacement, velocity and
acceleration.
The simulation is performed for two different types of ground vehicles, light-duty and
heavy-duty vehicles. Results show that the addition of the non-linear suspension
components in the dynamic model of the two vehicles decreases the vibration of the
vehicle. In case of sinusoidal road input the ride comfort performance is improved by
66.4% and road holding performance is improved by 37.2%. In case of unit step road input
the ride comfort performance is improved by 26.86% and road holding performance is
improved by 13.8%. By optimizing suspension design parameters for linear and non-linear
suspension the sprung mass acceleration is decreased by 71% and 90.9% under sinusoidal
road input respectively. Similarly it is reduced by 50% and 62.5% under unit step road
input respectively.
