Investigation of the cyclic inelastic capacity of steel beams through the use of the plastic collapse mechanism

The paper investigates the available ductility of the steel beams under cyclic action. The study is based on the concept of the plastic collapse mechanism, previously developed for monotonic loading, and further implements the concept of the initial cumulative deformation; it aims to calculate the main parameters that affect the rotation capacity of steel I and H beams made by European sections. The findings show that the loading type defined by the increasing or the constant amplitude, the number of cycles producing strength and the ductility degradation and the cross section conformation are the factors of primary importance whereas, in general, the steel quality and the material variability have a secondary detrimental effect.