高性能金屬斜撐結構系統之耐震性能研究---子計畫：特殊同心斜撐構架之斜撐構材耐震性能研究(III)

Abstract

對於強震區域而言，特殊同心斜撐構架 (Special Concentrically Braced Frame, SCBF) 是一種可有效的抵抗地震力之構架系統。不同於一般的抗彎矩構架，SCBF 的非彈性 變形乃根據斜撐構材與接合板受軸拉力降伏和受壓產生整體或局部挫屈而設計之。國 內常使用之斜撐構材大多是重型斷面，例如H-型鋼、H-型鋼加側板或箱型斷面。由 於國內習用之斜撐構材之實驗資料短缺，斜撐構材與其接合受拉壓之反覆遲滯行為需 要更進一步的了解。 本研究於第一年採用非線性有限元素分析進行斜撐構材與其接合之非彈性遲滯行 為之研究，藉由先前實驗結果先行驗證有限元素分析模型的準確性。第二年研究以實 驗方法進行國內常用斜撐與接合細節之反覆載重試驗，以研究其遲滯行為與強度，進 而變更試體之參數，以期達到經濟且具優良非彈性行為之斜撐與接合設計。本計劃為 第三年，擬進行斜撐構材面內挫屈型式之研究，面內挫屈不同於面內挫屈在於須將斜 撐構材之弱軸轉置構架面內，斜撐構材與接合板之連結需一連接板。此連接板之型 式、其與斜撐構材及接合板之接合設計、以及力量傳遞與非線性行為等皆須深入研 究。本計畫並將嘗試將斜撐構材兩端切削以達成面內挫屈，並於此切削區域提供塑性 行為以消能。研究方法擬進行有限元素分析與試體反覆載重試驗，以期對斜撐面內挫 屈之遲滯行為有更進一步之瞭解，針對接合板與連接板建立相關設計方法，以期為工 程實務之參考應用。

Special concentrically braced frames (SCBFs) are one of the effective earthquake-resisting frames used in the high seismic areas. Unlike the moment-resisting frame, SCBFs will behave with inelastic deformation depending on the braces and gusset plates which are designed to yield in axial tension and to buckle, globally or locally, in axial compression. The braces used in Taiwan are generally in the form of heavy braces, e.g., H-shaped structural steel, H-shaped steel with additional side plates, or box section steel. Due to lack of experimental results for the heavy braces, the cyclic behavior for heavy braces and their connections is needed to clarify. In the first year, this research was conducted using nonlinear finite element analysis to investigate the inelastic cyclic behavior of the braces and connections to gusset plates. Finite element modeling was validated by comparing the analysis results with previous experimental results. In the second year, the research is conducting experimentally to investigate the hysteretic behavior and strength of the heavy braces and gusset plate connection used in Taiwan. Furthermore, the specimen design parameters are varied to achieve the economy and the satisfactory inelastic behavior of the braces and gusset plate connections. This proposal is for the third year and the in-plane buckling of the braces will be studied. Unlike the out-of-plane buckling of the braces, the braces buckled in-plane are to be designed to have their minor axis in the plane of the frame, and a link plate is needed between gusset plate and the brace. The configuration, detailing, force transferring, and nonlinear behavior of the link plate require to be investigated. Another design method to achieve in-plane buckling of the brace will be designed by reducing brace section at both ends of the brace to create yielding zones to dissipate energy. Finite element analysis and experiment of cyclic testing will be conducted to study the hysteretic behavior of the braces bucked in-plane, to establish the design procedure for the gusset plate and link plate, and to be beneficial for the practice.