PSI - Issue 28

Jesús Toribio et al. / Procedia Structural Integrity 28 (2020) 2382–2385 Jesús Toribio et al. / Procedia Structural Integrity 00 (2020) 000–000

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applied at the bar ends generates a bending stress caused by the eccentricity of the inner crack, thus provoking a rotation in the sample, which increases with the crack deviation from the bar axis (Fig. 6).

1.04

1.20

d/D=0.3

d/D=0.5

1.03

1.15

K IA /K I,sym

K IA /K I,sym

1.02

1.10

K I /K I,sym

K I /K I,sym

1.01

1.05

K IB /K I,sym

K IB /K I,sym

1.00

1.00

0.99

0.95

0.00

0.05

0.10

0.15

0.20

0.00

0.05

0.10

0.15

0.20

 /D

 /D

(a) (b) Fig. 5. SIF ratio at point A K IA / K I,sym and SIF ratio at point B K IB / K I,sym vs . relative inner crack eccentricity ε / D : (a) d / D = 0.3; (b) d / D = 0.5.

(a) (c) Fig. 6. Initial and deformed cracked bar (contour bands correspond with the normal component in axial direction of the stress tensor): (a) ε / D = 0; (b) ε / D = 0.0875; (c) ε / D = 0.175. 4. Conclusions For eccentric circular inner crack in a round bar subjected to tensile loading as the crack eccentricity or the crack diameter increases so does the difference between the SIF values along the crack front. The maximum SIF raises with the eccentricity, while the minimum SIF decreases for small eccentricities and increases for high eccentricities. References Eshraghi, I., Soltani, N., 2015. Stress Intensity Factor Calculation for Internal Circumferential Cracks in Functionally Graded Cylinders Using the Weight Function Approach. Engineering Fracture Mechanics 134, 1–19. Guinea, G.V., Rojo, F.J., Elices, M., 2004. Stress Intensity Factors for Internal Circular Cracks in Fibers under Tensile Loading. Engineering Fracture Mechanics 71, 365–377. Irwin, G.R., 1957. Analysis of Stresses and Strain Near the End of a Crack Traversing a Plate. Journal of Applied Mechanics 24, 361–364. Li, W., Deng, H., Liu, P., 2016. Interior Fracture Mechanism Analysis and Fatigue Life Prediction of Surface-Hardened Gear Steel under Axial Loading. Materials 9, 843, 1–14. Nehila, A., Li, W., Zhao, H., 2018. Interior Failure Mechanism and Life Prediction of Surface Treated 17Cr-Ni Steel under High and Very High Cycle Fatigue. Fatigue & Fracture of Engineering Materials & Structures 41, 1318-1329. Nguyen, H.Q., Gallimard, L., Bathias, C., 2015. Numerical Simulation of Fish-Eye Fatigue Crack Growth in Very High Cycle Fatigue. Engineering Fracture Mechanics 135, 81–93 Tada, H., Paris, P.C., Irwin, G.R., 2000. The Stress Analysis of Cracks Handbook (3 th edition), ASME Press, New York, USA, 1973. (b)