Abstract

Electro-Rheological (ER) and Magneto-Rheological (MR) fluid based advanced suspension dampers are emerging to be the next generation of suspension dampers. ER damper and MR damper have gained wide spread attention in academia as well in auto industries due to their attractive features and promising performance potential to overcome the limitations of existing dampers in market. This work presents a comprehensive study of four different suspension dampers, where each are modeled, validated and assigned a set of parameters to facilitate a comparison of performance. The dampers considered include linear passive damper, two-stage asymmetric non-linear damper, ER damper and MR damper. The vibration and shock isolation performance of the dampers are compared using a four degree-of-freedom pitch plane ride model. A wide range of performance measure is considered in this investigation, namely--sprung and unsprung mass responses, relative motions, drift, pavement load etc. The study reveals superior vibration and shock isolation performance of ER damper and MR damper for vehicle sprung mass compared to linear passive damper and asymmetric non-linear damper. Since the dampers are designed as symmetric in compression and rebound, they are immune from ride height drifting problem. At higher frequencies (above 10 Hz), the dampers transmit higher load to pavement compared to other two. The study suggests that asymmetricity should be included in the design of these dampers to achieve improved performance over the entire frequency range. A properly tuned MR damper with controller to provide asymmetric characteristics has the most potential for superior performance for all responses.