Torsion and axial loads were applied using a dead-weight loading arrangement. In the computer simulation, the complete male and female splines are modelled and the load and restraints were designed to simulate the conditions in the experimental test rigs. A torque load is applied to the female spline and the end of the male spline is restrained against movement. A comparison of the predicted and measured values of torsional stress can therefore be used to provide an initial indication of the quality of the analysis. 2 and 3 show the computer model analyses axial distribution of root torsional stress compared with stresses derived from the strain gauge and photo-elastic measurements at the spline design load.
Good correlation is obtained in both cases.
Due to different specific loading of the photo-elastic model, the contact conditions are very different to the steel spline and this is reflected in the results, and encouragingly, also predicted by the analysis. Additional testing work carried out at Imperial College and the other project partners included a laboratory based high frequency reciprocating test rig with one optically transparent contact. The mechanism of fretting wear initiation and progression has been studied for a range of material heat treatment and coating combinations. A simple fretting wear model has also been developed for incorporation into the boundary element analysis software. Alternatively please contact Bob Adey for the format you need.