Abstract

This paper concerns with the study of influences of damper asymmetry together with the suspension kinematics and tire lateral compliance on the kineto-dynamic responses of a roll-plane half-car model. Such coupled analysis of kinematic and vertical and roll dynamic measures of the vehicle involving asymmetric suspension dampers has not been reported in the literature. A 4-DOF, roll-plane model of the road vehicle employing a double wishbone type suspension comprising a strut with linear spring and asymmetric damper is formulated for the analyses. The influences of asymmetric dampers are studied by comparing the sprung mass vertical acceleration, chassis roll angle and the dynamic tire forces, and the left- and right tires camber angle variation responses of the model with asymmetric dampers with those of the model with an equivalent linear damper under bump and pothole inputs. The influences of damper asymmetry are also investigated under rounded-step lateral excitations. The results of the study suggested that the responses are complex functions of damper asymmetry ratio, defined as the ratio of damping coefficient in rebound to that in compression, vehicle forward speed and type of input. The study further suggests that a very low compression mode damping is undesirable from both ride and handling dynamic perspectives.