ABSTRACT
The low-cycle fatigue behaviour of moment resisting steel frames is investigated. Damage is attributed to plastic rotations at members or joints. Fatigue curves are expressed by the relevant rotation capacity under monotonic loading and the value of the slope. A linear damage accumulation low and the rain-flow method for counting of cycles are applied. Parametric studies for several frames subjected to various earthquake records are performed. The influence of a series of factors like the type of frame, the type of record, semi-rigidity of joints, level of vertical loading, slope of the fatigue curves all of which significantly affect the fatigue behaviour was investigated.
