Influence of modelling of steel link beams on the seismic response of EBFs

This paper investigates the effectiveness of some common and simple models of steel link beams in theseismic assessment of eccentrically braced frames. These models are based on the Euler-Bernoulli beamwith concentrated flexural plastic hinges and consider ending springs to simulate the inelastic shear andflexural responses of the link. They do not allow the effects of both isotropic and kinematic hardening tobe separately evaluated but considers an equivalent kinematic hardening. The benchmark is representedby the seismic response obtained by means of a simple but refined link model that has recently been pro-posed by the writers and that takes into account both kinematic and isotropic hardening. The accuracy ofthis model has been proved by several numerical tests on short, intermediate length and long links. Toperform an extensive parametric investigation, the numerical analyses are first carried out on equivalentsingle-storey systems subjected to artificial accelerograms. Then, multi-storey systems subjected toeither artificial or natural accelerograms are investigated. These systems are characterised by differentmechanical lengths of the links and, in the case of multi-storey systems, by different numbers of storeys.