Hybrid modelling and simulation of the torsional vibration of vehicle driveline systems

Abstract

Vehicle drivelines are lightly damped non-linear systems possessing many degrees of freedom with dynamic interactions between the various subsystems. There are many sources of excitation such as torsional impact caused by the take-up of backlash in the power train system. Such sources of excitation exist in transmission backlash, in driveline splines and in pinion to ring gear contact in the differential. Abrupt application or release of the throttle in slowly moving traffic or rapid engagement of the clutch can be followed by noise and vibration responses referred to in the industry as ‘clonk’. This paper presents a method of modelling a vehicle driveline which can identify the phenomena known as ‘clonk’ and ‘shuffle’. This model is based on the assumption that vehicle drivelines can be considered as partially lumped and partially distributed, which for systems of this type is wholly appropriate. In doing this it is possible to derive an analytical solution to the governing equations, which has not been considered previously. The results from this model are compared with a totally lumped model of the vehicle driveline for comparison.