Method for calculating a global dynamic factor KAV in gears subjected to variable velocity and loading conditions

The present paper aims to propose a method, in ISO Standard environment, in order to calculate a single global dynamic factor KAV, replacing both KA and KV, in case of gears subjected to variable velocity and loading conditions. This procedure, based on the Miner damage rule, allows to process a given load spectrum and to calculate a value of the equivalent tangential force that includes all dynamic effects; this force value is useful for bending and pitting calculation of the service life. In this work a practical case for bending strength is presented, based on a recorded flight mission, referring to a gear box for aerospace applications. Obtained results in terms of equivalent forces and global dynamic factor values have been compared to those calculated by means of the classical ISO Standard formulae, based on the corresponding experimental data.