Photo: Jonne Renvall, Tampereen yliopisto
In his doctoral dissertation, MSc (Tech) Erkka Virtanen studied how hidden (subsurface) fatigue cracks initiate and grow inside large bevel gears used in heavy and marine industries. Using experiments and simulations, he showed that cracks can form below the surface but typically grow slowly and do not immediately lead to gear failure. Current industry practices rely on periodic inspections, and clear criteria for acceptable subsurface damage are lacking. The findings can help engineers better assess gear condition, avoid unnecessary part replacements, and improve the safety and cost-efficiency of machinery.
The doctoral dissertation of MSc (Tech) Erkka Virtanen in the field of Materials Science titled Initiation and growth of subsurface fatigue cracks in large-size bevel gears will be publicly examined at the Faculty of Engineering and Natural Sciences at Tampere University on 26 June 2026.
The Opponents will be Professor Karsten Stahl from the Technical university of Munich in Germany and Professor Reza Talemi from KU Leuven in Belgium. The Custos will be Associate Professor Auezhan Amanov from the faculty of Materials Science and Environmental Engineering.