Numerical investigation of the effect of hole reaming on fatigue life by cold expansion

Abstract

The reaming process of the 6061 aluminum alloy plate after cold expansion with split sleeve was simulated by finite element (FE) method based on Abaqus/CAE, the relationship between the reaming depths and the distribution of residual stress fields is obtained by analysis. The fatigue lives of the plate under different reaming depths were calculated by using the fatigue analysis software FE-SAFE, and verified by fatigue tests. The results show that reaming after expansion will increase the residual compressive stress at the hole edge on the entrance surface. In addition, the fatigue life of the specimens increases with the increase of the reaming depth, and the best fatigue gain of the specimen is obtained when the reaming depth of 0.5 mm.

Factors Influencing Residual Stresses in Cold Expansion and Their Effects on Fatigue Life—A Review

“…Proper reaming of the hole wall can correct the roundness of the hole and remove potential fatigue micro-cracks, ensure the continuity of hole collection and micro-continuity, and improve the fatigue life of the hole [57]. However, the removal of the material will inevitably change the elastic-plastic state of the pore wall material, thereby affecting residual stress and microstructure, as shown in Figure 7c [58]. Figure 7d shows the effect of different reaming amounts on the residual stress distribution.…”

Research on the Residual Stress Field of a Compression Bushing-Lug Plate in Cold Expansion Strengthening

“…The results show that the maximum values of circumferential residual compressive/tensile stresses in both the "infinite" and "finite" domains increase with the development of the interference values, and higher values of positive stresses are obtained at the boundary of the "finite" domain [24][25][26][27]. In addition to this, the main parameters affecting bushing repair can be analyzed qualitatively based on fatigue theory [28][29][30][31]. The results showed that the fatigue quality of the bushing decreases with the increase in the bushing's outer diameter.…”