三層樓鋼管混凝土柱暨挫屈束制斜撐構架行為分析

Abstract

2003年於國家地震工程研究中心進行一三層樓鋼管混凝土柱暨挫屈束制斜撐構架試驗，目的為探討各式鋼管混凝土柱接鋼梁之接頭與挫屈束制斜撐在實體構架之耐震消能行為，本文以非線性結構分析程式DRAIN-2DX進行構架分析與結果比較。於構架分析前先對梁柱接頭子結構進行模型建立與分析，待子結構模型模擬結果符合實驗結果，再進行三層樓構架模型之建立與分析比較。由結果比較顯示，DRAIN-2DX對於梁柱接頭子結構試驗之模擬結果良好，可預測梁柱接頭之整體勁度與強度；於構架分析結果尚稱良好，第一階段試驗之分析結果較佳，但隨著構架之局部破壞與補強，第二階段試驗之模擬結果誤差亦隨之累積。構架分析時，鋼梁之模擬須考慮樓板效應造成之正負彎矩強度之不同，可獲得較佳之分析結果。最後進行非線性側推分析，採交會區為剛性或半剛性之模擬，分析結果顯示交會區之剪力-剪力變形關係將影響構架之極限強度，半剛性交會區將略為降低構架之極限強度，惟不影響構架之彈性勁度。

A 3-story frame with concrete-filled tube columns (CFT) and buckling restrained braces was tested in October 2003. The purposes of the test are discussing the seismic behavior of steel beam to CFT column connections and BRB in frame. For frame analysis and comparison of the result, nonlinear structural program, DRAIIN-2DX, is used. First step of analysis is modeling and simulating the sub-structure by DRAIN-2DX, then comparing the results with test. When the results of sub-structure model are matched with experiment, frame analysis is proceeded. Based on comparison of analysis and experiment, the results of simulating sub-structure are excellent, DRAIN-2DX can effectively predict the global stiffness and strength. For the frame analysis, the results of simulation in Phase I are fine. But because of the failure in the detail of frame, the error in simulating is added in Phase II. It is observed that considering the slab effect on the flexural strength of the steel beam leads to more accurate analysis results. Pushover analyses were performed to study the effect of joint stiffness of the panel zone on the nonlinear behavior of the frame. Compared to rigid joint, semi-rigid joint modeling results in slightly lower ultimate strength of the frame, but not the elastic stiffness of the frame.