Investigation of crack propagation path in tube gears.

In this paper, the crack propagation behaviour in tube gears has been investigated. This kind of gears find application in aerospace and in particular in helicopter drivelines. For this reason, an accurate design against catastrophic failure due to particular crack propagation paths, has to be performed. In this work, the effect of tube length and rim thickness and also speed on crack propagation path has been analysed by means of extended finite elements models. In particular, to better understand the effect of speed, the changes in stress intensity factors KI and KII have been considered. Particular crack propagation shapes (wave propagation) have been found in some cases where the length ratio is particularly high.