POLITECNICO DI MILANO Department of Mechanical Engineering Doctoral Programme In Mechanical Engineering SHEAR-MODE PROPAGATION OF SHORT CRACKS UNDER ROLLING CONTACT FATIGUE Supervisor: Prof. Stefano BERETTA Co-Supervisor: Dr. Ioannis V. PAPADOPOULOS Tutor: Prof. Stefano BRUNI The Chair of the Doctoral Program: Prof. Giampiero MASTINU 2011 - XXIV Cycle Doctoral Dissertation of: M. Gabriella TARANTINO ID number. 738589