PSI - Issue 13

Taro Suemasu et al. / Procedia Structural Integrity 13 (2018) 1088–1092 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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Fig. 5 Matching of the fatigue crack surfaces. (a) and (b) are the fatigue crack failure surfaces of the left side of the pre-crack.

4. Conclusions

In this study, we aimed at quantitatively evaluating RISS caused by the frictional force generated between fatigue crack surfaces as a factor affecting the fatigue crack propagation in rolling fatigue. In fatigue cracks caused by RCF, fatigue crack propagates in the texture formed by cyclic rolling contact, and therefore, a fatigue crack propagation test under Mode II loading was conducted using a material having texture. The obtained results are described below. 1) It can be observed that there was a gap between the fatigue crack surfaces at zero loading. As the width of the gap between the fatigue crack surfaces was almost unchanged in the entire fatigue crack, and there was no trace of the contact of the fatigue crack surface, it is considered that the gap between the fatigue crack surfaces was caused not by wear but by fatigue crack propagation. 2) It was observed from the quantification results that the amount of decrease in the Mode II stress intensity factor owing to the contact between fatigue crack surfaces was sufficiently small to be ignored. It is considered that RISS effects were sufficiently small to be ignored because the gap between the failure surfaces was formed owing to fatigue crack propagation. Beynon, J.H., Garnham, J.E., Sawley K.J., 1996. Rolling contact fatigue of three pearlitic rail steels. Wear 192, 94 – 111. Garnham, J.E., Davis, C.L., 2008. The role of deformed rail microstructure on rolling contact fatigue initiation. Wear 265, 1363 – 72. Hamada, S., Fukudome, S., Suemasu, T., Koyama, M., Ueda, M., Noguchi, H., 2018a. Test method for Mode II fatigue crack propagation in a small specimen. Part I: Mechanical examination. Engineering Fracture Mechanics, submitted for publication. Hamada, S., Fukudome, S., Suemasu, T., Koyama, M., Ueda, M., Noguchi, H., 2018b. Test method for Mode II fatigue crack propagation in a small specimen. Part II: Experimental examination. Engineering Fracture Mechanics, submitted for publication. Hamada, S., Fukudome, S., Koyama, M., Ueda, M., Noguchi, H., 2018c. Phenomenon and mechanism of fatigue crack propagation under Mode II loading: An example of cold rolled sheet steel. International Journal of Fatigue, submitted for publication. Paris, P.C., Sih, G.C., 1965. Stress analysis of cracks. In: ASTM Special Technical Publication 381 (STP 381): Fracture Toughness Testing and Its Applications. Philadelphia, PA: American Society for Testing and Materials, 30 – 83 Westergaard, H., 1939. Bearing pressures and cracks. Transactions of the ASME, Journal of Applied Mechanics 6, A-49 – A-53. Zhai, T.G., Lin, S., Xiao, J.M., 1990. Influence of non-geometric effect of PSB on crack initiation in aluminium single crystal. Acta Metallurgica et Materialia 38, 1687 – 92. Zhai, T., Martin, J.W., Briggs, G.A.D., 1995. Fatigue damage in aluminum single crystals — I. On the surface containing the slip burgers vector. Acta Metallurgica et Materialia 43, 3813 – 25. References