Parametric excitation and wavelet transform analysis of a ground vehicle propeller shaft

Abstract

This paper proposes a numerical model for analyzing torsional vibration of a ground vehicle propeller shaft system. By considering the elasticity and energy of the propeller system, a Lagrangian approach has been used to derive the equation of motion, yielding a highly nonlinear three degree-of-freedom system with five coupled inertias. The model takes into account the dynamics of a Hooke’s joint, a crack-induced parametric excitation, tractive torque at the driving wheels and transient vibration of a rear drive ground vehicle transmission. The forces exciting the vibrations of the propeller shaft system are evaluated by quantifying the tractive forces at the road wheels, Hooke’s joint force, the crack force and the forces emanating from the engine through the clutch and gear box. Subsequently, the forces are projected onto the propeller shaft by either direct coupling or by gearing. Consequently, the nonstationary response of the system in various scenarios has been determined and evaluated by a wavelet transform. By analysis, it is demonstrated that the model is useful for investigating nonlinear vibration of a typical propeller shaft system used in light ground vehicles.