H- ve I- enkesitli Avrupa profillerinden teşkil edilen bağ kirişlerinde pekleşme katsayısının incelenmesi

In steel eccentrically braced frames (EBF), plastic deformations are confined to link beams under strong earthquake ground motions and seismic energy is dissipated through yielding of link beams. For an EBF, the capacity design principle requires that connections, columns, braces, and beam segments outside of the link be designed to remain essentially elastic while the link beams fully yield and strain harden during the design earthquake. For the design of all structural components other than link beams, the required strengths must be obtained with the combination of the factored gravity forces plus the forces produced by the adjusted shear strength of the link that contains the effect of strain hardening, using the load combinations including the overstrength seismic load. Strain hardening factors which are considered to obtain overstrength factor are specified in TBSC (Turkey Building Seismic Code) 2018 for the structural components outside of the link. The aim of this study is to provide comprehensive study on the strain hardening factor for a wide range of link beams made of European H- and I- shapes (IPE and HEB) profiles. A total of 280 finite element analyses have been conducted under quasi-static cyclic loading and the strain hardening factors for short, intermediate and long link beams have been studied. Results show that strain hardening factor of 1.25 is unconservative for link beams. Therefore, strain hardening factors for short, intermediate and long links, were also proposed based on the normalized link length.