Design of Shaft Respecting the Fatigue Limit for Ultra-High Number of Cycles

Advances in engineering solutions in recent few decades caused that conventional fatigue limit (for steels and cast irons given for number of 107 cycles) is no more sufficient. Construction parts of newly introduced transport vehicles, operating at high velocities and at long distances, reach during their lifetime very high numbers of loading cycles, in order of 109. For this reason, values of fatigue limits for 109 cycles must be considered in design and construction of transport vehicles. In this study, authors present how dramatically will change the design of shaft, when fatigue limit for 109 cycles is considered.