Solving Fatigue Problems for Combined Loading by Static Torsion and Reversed Cyclic Bending

The fatigue life and limit state of prismatic specimens under static torsion and reversed cyclic bending are analyzed using a fracture model that describes the relationship between the maximum and minimum amplitudes of a repeated stress cycle in the form of exponential transcendent function and the concept of equivalent stresses. The stress of a reversed cycle that reduces a repeated stress cycle to a reversed cycle in a fixed number of cycles to fracture is chosen as equivalent stress. The calculated results are validated experimentally for specimens made of alloyed steels and aluminum alloy.