링크의 초과강도 예측에 의한 편심가새골조의 역량설계

초록

According to the capacity design of eccentrically braced frames (EBFs), non-dissipative members such as columns, link-exterior beams, andbraces must remain within the elastic region when a fully-yielded and strain-hardened link transmits force to them. The current AISC 341standard suggests a strain-hardening factor (SHF) of 1.25 for a link under capacity design, regardless of its properties. However, all the links in anEBF are not likely to yield simultaneously to the extent to which the overstrength corresponding to 1.25 times their expected strength is attained,especially for high-rise buildings. Considering this phenomenon, a technique to predict the SHF of links at the limit state of the structure isproposed in this paper. The exact prediction of the links’ SHF could save structural quantities dramatically while achieving the principle ofcapacity design. To validate the effectiveness of this technique, SHF values predicted by conducting linear analysis were compared with thoseevaluated by nonlinear analysis. Furthermore, the maximum demand-to-capacity ratios of the non-dissipative members were calculated to verifywhether they would remain elastic at the limit state of the structure. Consequently, EBFs designed by the proposed method showed substantiallyeconomical quantities through the exact prediction of the SHFs, and the intention of capacity design was successfully achieved.

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