Cyclic Variation of Residual Stress Induced by Tool Vibration in Machining Operations

In machining, due to the tool vibration the forces, temperatures and stresses vary during the cutting process, so as the residual stresses over the machined surface. This variation of the residual stress has never been measured and, therefore, imposes new experimental challenges. The objective of this work is to correlate the variation of the residual stresses along the cutting path with the frequency of the surface geometrical defect generated by the vibration of the tool holding system. In order to perform such correlation a hybrid experimental/analytical approach was applied for an austenitic stainless steel, AISI 316L. Residual stresses were analyzed in the machined specimen along the cutting path using neutron diffraction. The results show a cyclic variation of the residual stresses, which can be detected when considering the frequency of the tool vibration. The frequency of the tool vibration is also correlated with the topology of the surface.