Torsional Finite Element Analysis of Driveline Torsional Vibration for a Front Wheel Driveline Vehicle Development

Abstract

The purpose of this paper is to study the torsional vibration of Front Wheel Driveline (FWD), to avoid the torsional resonance with vehicle, to reduce the torsional vibration and gear rattle noise, and to find out the sensitive factors for controlling the torsional vibration. A torsional finite method is used to establish a 4D-freedom torsional vibration analysis model for FWD system. The natural frequency and modal shapes are calculated, and the torsional vibration characteristics are acquired by system excitation. A 4D-freedom torsional vibration model is established, and numerical simulation for the characteristics of the driveline is analyzed. An optimal method is established to reduce driveline torsional vibration and gear rattle noise. Many factors, such as rotational shaft unbalance, shaft offset its rotation center due to the clearance of universal joints, splines and other components, and non-straight of driveshaft, influence torsional vibration. In order to simplify the analysis model, these factors are not considered. A torsional vibration analysis model with torsional finite method is established, a matching method between system stiffness and damping is presented to reduce driveline torsional vibration and gear rattle noise. In the third order mode of the driveline system, the input shaft of the transmission has the biggest amplitude and its modal frequencies vary with different gears. In order to avoid torsional resonance with other components, the torsional modal frequency could be changed by modulating the stiffness of clutch, driveshaft and tire. The NVH tests show that it’s effective to reduce the torsional vibration by modulating the clutch stiffness and torsional angle.

F2012-J02-001