Study on the sensitivity of gear stiffness to tooth crack length and location for diagnostic applications

摘要

A numerical simulation of the dynamic behaviour of the system is surely a convenient means to perform preliminary testing of a diagnostic system, to support the interpretation of experimental results and to investigate on a wider range of operating conditions and defects. In this work the gear overall stiffness was evaluated statically as function of the gear angular position by means of FE models of the mating wheels and gear structure, taking into account the deformation of the teeth under load and the presence of a tooth crack of different length and at different locations. The so calculated stiffness was then employed to simulate the gear transmission dynamic behaviour in steady conditions with a lumped non-linear model in a Matlab/Simulink environment. Standard and non-standard diagnostic vibration indicators have been calculated for the synchronously averaged virtual acceleration signal of the progressively faulted gear in order to compare their effectiveness in fault identification.