Numerical simulation of the reaming process in aluminium 2024-T351 – analysis of the evolution of the material stress state

Abstract

 In aircraft assemblies, holes for fastening are critical areas from 
where fatigue damage can be initiated, especially for metal 
parts. Depending on the operating conditions of the various 
stages of the machining process of the hole (drilling, reaming, 
cold expansion, second reaming), the manufacturers observe 
significantly different fatigue strength of the structures. 
To optimize the behavior of the aircraft assemblies, the 
manufacturers want to understand the impact of the whole 
machining process of the hole on the material characteristics 
of the part. They investigate particularly the residual stress 
state in the hole edge zone which can be significantly different 
depending on the operating conditions. 
This paper investigates the influence of the reaming process 
in an aluminum 2024-T351 part with initial material state not 
clean of mechanical stress. Indeed, before the final reaming, 
the parts undergo at least a drilling operation, and sometimes 
a cold expansion operation. For this study, in collaboration with 
Airbus, the simulated reamed part has been pre-stressed by the 
cold expansion process. Both processes are simulated using a 
finite element model with Abaqus. The implemented strategy 
to simulate the reaming process is based on the progressive 
deactivation of mesh elements. The obtained results show a low 
relaxation of the circumferential and radial residual stresses in 
the part during the reaming simulation.