The RODEO project has produced the expected results. 2D and 3D modeling work on the residual stresses induced by a helical burnishing operation in aluminum holes was carried out and allows to better understand and control this phenomenon.
An innovative combined drilling and burnishing tool has been developed and tested. The results obtained show a significant increase in the level of residual stresses in the wall of the hole, compared to a conventional orbital drilling process, especially on smaller diameter holes. Fatigue tests are continuing to correlate the results observed in helical burnishing with the fatigue strength of aeronautical assemblies.
A compact and lightweight orbital drill head has also been designed and fully tested. Its performance and very light weight make it possible to envisage its use at the end of a robotic arm.
The adaptation of the drilling head on robotic arms from KUKA has been studied dynamically, in order to define and optimize the phenomena of rigidity and resistance to vibrations. The IIWA arm was ultimately found to lack rigidity for the intended application, but the KR60 arm proved to be perfectly suited.