Theoretical investigation of the improved nonlinear dynamic model for star gearing system in GTF gearbox based on dynamic meshing parameters

Abstract

In the previous study, the gear meshing parameters are usually treated as constants, however, the translational motion, caused by bearing deformation, will lead to the variation of these parameters. In order to investigate the dynamic response of the GTF (Geared Turbofan engine) gearbox that more close to the actual working condition, the improved nonlinear dynamic model of GTF gearbox is proposed in this paper, in which the structure-based time-varying gear meshing parameters and multiple nonlinear clearances are fully considered, including time-varying mesh stiffness, pressure angles, contact ratios, position angles, and dynamic gear backlashes. Afterwards, the improved model is compared with the previous model, and their dynamic characteristics are demonstrated in time, and frequency domain. The results indicate that the nonlinear dynamic behaviors could be altered along with tooth impact state due to the time-varying meshing parameters, which could provide better understanding of the structural design and vibration control of the system.