Créé le : 09/05/2019
Drilling can a affect the integrity of the surface of a mechanical component and reduce its fatigue life. Thus, drilling parameters such as lubrication or drilling velocity must be optimized to ensure a satisfactory residual mechanical state of the hole surfaces. Unfortunately, experimental tests are time consuming and it is not easy to observe the cutting process because of the confinement of the drill zone. The literature does not exhibit any numerical simulation able to simulate 3D thermomechanical phenomena in the drill zone for holes large depths. Therefore, residual stresses can not be easily simulated by means of the only drilling parameters. The aim of this article is to propose a new numerical approach to compute drilling residual stresses for holes of large depths. A rst simulation is developed to simulate heat transfer by means of a 3D thermo-viscoplastic simulation in a new Rigid-ALE framework allowing the use of large calculation time steps. Then, a transformation process is implemented to rebuild the Lagrangian thermal history of the machined component. Finally, a thermo-elasto-plastic simulation is carried out to compute residual stresses in the nal workpiece. In this paper, the method is applied to an 316L austenitic stainless steel in the case of an unlubri cated hole. The computed residual stresses are compared to experimental measurements.
Author : U. Masciantonio, Cetim