This work is licensed under a Creative Commons Attribution-NonCommercial- NoDerivatives 4.0 International License. This is a postprint version of the following published document: Rubio, P., Bernal, J., Rubio, L., & Muñoz-Abella, B. (2019). Study of the propagation of concave semi- elliptical shaped breathing cracks in rotating shafts. International Journal of Fatigue, 129, 105214. DOI: 10.1016/j.ijfatigue.2019.105214 © 2019 Elsevier Ltd.