A comparison of gear mesh stiffness modeling strategies

Abstract

Gearboxes are prone to numerous faults that require vibration health monitoring to ensure proper operation. Monitoring methods typically employ casing mounted accelerometers. This data is difficult to interpret because of the many gear mesh frequencies present and is further complicated by the presence of significant amounts of noise. Several different dynamic system modeling strategies are currently being used by researchers to identify diagnostic indicators of gear health: a strength of materials based lumped parameter model, non-linear quasi-static finite element modeling, and rigid multi-body kinematic modeling with nonlinear contact stiffness. This study contrasts these methods of modeling gear dynamics by comparing their predicted stiffness cycle and its effect on dynamic response. A pair of ideal high contact ratio spur gears and a pair with a low contact ratio are considered. Data from experiments are shown for the high contact ratio pair. Results show that stiffness may be poorly matched either by exclusion of significant compliance, incomplete sensitivity and convergence studies, or by high frequency variations due to discretization. ©2010 Society for Experimental Mechanics Inc.