PSI - Issue 39

Giovanni Pio Pucillo et al. / Procedia Structural Integrity 39 (2022) 700–710 Author name / Structural Integrity Procedia 00 (2019) 000–000

708

9

1200

1000

800

600

400

True stress [MPa] 200

0

0

0,04

0,08

0,12

Logarithmic plastic strain [mm/mm]

Fig. 9. True stress vs. logarithmic plastic strain curve of the R260 rail steel.

The interference between the tapered mandrel and the hole was simulated by imposing, and then removing, a uniform radial displacement, u , to the nodes belonging the hole surface (Fig. 8). For more details see (Pucillo et al. 2020a; 2020b). Being the percentages of CE used for the experiments equal to 2.0% and 4.0%, the applied radial displacements were, respectively, 0.06 mm and 0.12 mm. The results are shown in Fig. 10, in terms of hoop residual stresses along the transversal mid-section of the specimen.

200

0

Exp 2%

-200

Exp 4%

x

-400

x

-600

0

5

10

15

20

Hoop Residual Stress [MPa]

x – Distance from the hole edge [mm]

Fig. 10. Residual stresses for different percentages of expansion.