Simulation study on residual stress and fatigue life of the 7050 lug holes after cold extrusion strengthening
ZHENG Zeting
LI Xiangfeng
YI Zhidong
TANG Wei
LI Wensheng
LIU Yexin
Abstract：[Objective]Based on the fact that the quality of cold extrusion strengthening is closely related to the selection of process parameters,this study investigates the effects of different process parameters on the residual stress and fatigue life of 7050 aluminum alloy lug holes after cold extrusion strengthening.[Methods]Firstly,the distribution and variation of residual stress in 7050-T7451 aluminum alloy lug holes with PH13-8Mo pressed-in bushings after cold extrusion strengthening were explored by using the finite element method.The validity of the established finite element model was confirmed through energy methods and pull-out force tests.Subsequently,the influence patterns of different process parameters on the fatigue life of lug holes were explored based on the finite element fatigue analysis software FE-Safe.Finally,fatigue tests were conducted to verify the reliability of the simulation model and results.[Results]The results indicate that both excessively large and small fillet radii of the mandrel transition are detrimental to improving the fatigue life of the lug holes.When the fillet radius of the mandrel transition is approximately 2 mm,the fatigue life of the lug holes is maximized.With the increase of the bushing reaming allowance,the fatigue life of the lug holes first increases and then decreases,reaching the longest fatigue life at a reaming allowance of about 0.8 mm.Additionally,the larger the installation clearance between the hole and the bushing,the shorter the fatigue life of the lug holes.
Keywords：Cold extrusion strengtheningFinite element simulationFE-SafeResidual stressFatigue life
Publication Date：2026-01-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 33-41 )