多層多跨具自復位梁柱接頭隅撐構架之耐震性能研究

Seismic performance of multi-bay-multi-story knee braced frames with dual self-centering mechanisms

涂崢嶸(Cheng-Jung Tu)

指導教授 ： 許協隆

國立中央大學/工學院/土木工程學系/碩士(2015年)

摘要

隅撐抗彎構架為近年來發展之新型結構系統，其可改善抗彎構架側向勁度不足之問題，亦可有較同心斜撐構架良好之韌性，然當隅撐構架受側向力作用，受壓側之隅撐會產生挫屈行為，導致構架強度驟降，故近年來發展了雙重自復位機制以改善此問題，而雙重自復位機制由具自復位梁柱接頭與自復位隅撐組成。由於實際工程應用上，結構係屬多層多跨形式，故本研究針對具雙重自復位多層多跨構架進行反覆載重試驗，以界定其耐震性能。研究結果顯示，雙重自復位構架可較同尺度之抗彎構架提升 1.66~1.69 倍之構架強度，其勁度亦可提升約 2.91 倍。研究中亦發現，自復位梁柱接頭配置角鋼摩擦消能機制可較無配置者提升約2.38倍之能量消散。另構架在預力系統保持彈性階段時，皆具有良好之自復位能力，可有效降低結構之殘餘變形，且當雙重自復位構架之上層與下層梁柱接頭之結合彎矩比例為1:1.5時，在相同頂層位移下，較上層與下層梁柱接頭之結合彎矩比例為1:1時，提供構架較佳變形能力。研究結果證實，雙重自復位機制可提供構架良好之變形能力與強度，並可有效延後梁構件降伏時機，達到提升結構耐震性能之目的。

關鍵字

多跨多層構架 ； 雙重自復位機制 ； 能量消散 ； 耐震效能

並列摘要

Knee braced moment resisting frame (KBRF) has been developed in recent years. The KBRF system possesses higher stiffness than the moment resisting frame (MRF) and larger ductility than the concentrically braced resisting frame (CBRF), thus is a suitable structural form for earthquake-resistant purposes. However, when the KBRF is subject to heavy cyclic load, the knee braces that contribute to the structural strength will reach the buckling stage, causing major loss in structural performance. In order to improve the structural performance of the KBRF system, a modified design using dual self-centering mechanisms in the knee brace members and the beam-to-column connections was proposed in this study. A set of copper plates were used in the beam-to-column connections to dissipate energy through friction mechanism. A series of cyclic loading tests were conducted on the multi-bay-multi-story KBRFs to evaluate their performance.
It was found from the tests that the strength, stiffness and energy dissipation capacity of KBRF with dual self-centering mechanisms was higher than the MRF with equivalent dimensions. Test results also showed that the major structural members, including beams and columns, remained intact when the structural was subject to large drift, which justified the effectiveness of the proposed method. Further comparisons on the structural performance suggested that the ratio of joint decompression strength between lower and upper stories be approximately 1.5 so that higher structural performance could be achieved.

並列關鍵字

Multi-bay-multi-story frame ； Dual self-centering mechanisms ； Energy dissipation ； Seismic performance

參考文獻

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