Development of Plastic Hinges in Steel and Composite Beams of Eccentrically Braced Frames

The frame structures with eccentrically braced frames (EBF) are used world-wide and represent the alternative to the concentrically braced frames (CBF). The dissipative elements of eccentrically braced frames are characterized by the forming of plastic hinges, situated at the extremities of frame elements, preferably in the beams, and only at limit states in columns. The strength and ductility of EBF is directly related to the strength and ductility of the links. The seismic energy is dissipated by means of elasto-plastic shear cycles (for the short link), bending cycles (for the long link) and shear and bending cycles (for the intermediate link). This paper presents numerical studies with the objective to investigate the behaviour of 2D steel and composite eccentrically braced frames under seismic loading with active links which yield in bending.