預力鋼梁與鋼筋混凝土柱自行復位接頭之耐震行為研究

Abstract

利用預先施加於梁柱系統之預力以抵抗地震之效應為預力建築構造的特色，此種預力結構於受震過程中經由梁柱接合介面開合及預力鋼鍵之拉力而使結構物具有大變形後自我復位之能力，但有遲滯消能能力小的缺點。因此本研究著重於以反覆載重實驗的方式探討鋼梁與鋼筋混凝土柱以後拉預力鋼鍵的方式接合後的力學行為及抗震性能，並在鋼梁翼板外側與柱間提供削切型鋼板來增加接頭區的遲滯消能能力。實驗結果顯示(1) 含挫屈束制削切型鋼板可以有效增加梁柱接合的消能能力、(2) 預力梁柱接合系統可確保梁達到0.04弧度層間側位移角而無強度遞減之情形、及(3) 鋼梁在0.05弧度層間側位移角時因挫屈造成初始預力損失及自我復位能力的消失。本研究並以有限元素分析程式(ABAQUS)模擬試體以探討鋼梁在預力及撓曲載重作用下的行為。

The seismic performance of post-tensioned steel connections for moment-resisting frames was ewamined experimentally and analytically. Cyclic tests were conducted on three full-scale subassemblies, which had two steel beams post-tensioned to a reinforced concrete column (RCS) with high-strength strands to provide recentering response. Reduced flange plates (RFPs) welded to the column and bolted to the beam flange were used to incrase the dissipation of energy. Test results indicated that (1) the proposed buckling-restrained RFP was effective in dissipating energy in axial tension and compression, (2) the subassemblies could reach an interstory drift of 4% without strength degradation, and (3) buckling of the beam occurred at an interstory drift of 5%, causing a loss of the strand force, the recentering response, and the moment capacity. A general-purpose nonlinear finite element analysis program (ABAQUS) was used to perform a correlation study. The behavior of the steel beam under both post-tensioning and flexural loadings was described based on the experimental investigation and finite element analysis.