PSI - Issue 19

L.C. Araujo et al. / Procedia Structural Integrity 19 (2019) 19–26 L.C. Araújo et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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7. Conclusions As it was observed, it is possible to calibrate known multiaxial fatigue models using the √ parameter obtained for internally defective materials, specifically DIN 42CrMo6 steel, considering the area of the non-metallic inclusions of the material. It was shown that modeling the effect of natural defects in this steel is possible with classical models. The use of this method spends much less time and resources in the calibration of multiaxial models, when compared to traditional methods. The experimental data of combined in-phase axial-torsional loads appears to follows the model’s predictions trend as shown by the fact that most data points are within 5% error bands. The proposed model is useful to consider the size of a component in the determination of the fatigue limit with the √ parameter, which for mechanical design purposes can be considered as an advantage, once with a more conservative approach the risk of failure reduces. Acknowledgements The authors of this work would like to acknowledge the financial support provided by FAP-DF by means of the project entitled “ Fadiga em Virabrequins de Grupos Geradores ”. Araújo, J. A. et al. (2011) ‘On the characterization of the criti cal plane with a simple and fast alternative measure of the shear stress amplitude in multiaxial fatigue’, International Journal of Fatigue , 33(8), pp. 1092 – 1100. Crossland, B. (1956) ‘Effect of large hydrostatic pressures on the torsional fatigue strength of an alloy steel’, International conference on fatigue of metals , 6(3), p. 12. E466- 15 (2015) ‘Practice for conducting force controlled constant amplitude axial fatigue tests of metallic materials’, in ASTM Book of Standards . Endo, M. and Ishimoto, I. (2006) ‘The fatigue strength of steels containing small holes under out -of- phase combined loading’, International Journal of Fatigue , 28, pp. 592 – 597. Findley, W. N. (1959) ‘A theory for the effect of mean stress on fatigue of metals under combined torsion and axial load or bending.’, Journal of Engineering for Industry , 81, pp. 301 – 306. Murakami, Y. (1994) ‘Inclusion rating by statistics of extreme values and its application to fatigue strength prediction and quality control of materials’, Journal of Research of the National Institute of Standards and Technology , 99(4), p. 345. Murakami, Y. (2002) Metal Fatigue: Effects of Small Defects and Nonmetallic Inclusions . Ekevier Science Ltd. Susmel, L. and Lazzarin, P. (2002) ‘A bi -parametric Wöhler curve for hig h cycle multiaxial fatigue assessment’, Fatigue and Fracture of Engineering Materials and Structures , 25(1), pp. 63 – 78. Susmel, L., Tovo, R. and Lazzarin, P. (2005) ‘The mean stress effect on the high -cycle fatigue strength from a multiaxial fatigue point of view’, International Journal of Fatigue , 27(8), pp. 928 – 943. Yanase, K. and Endo, M. (2014) ‘Multiaxial high cycle fatigue threshold with small defects and cracks’, Engineering Fracture Mechanics . Elsevier Ltd, 123, pp. 182 – 196. References