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(I)

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受軸拉力作用降伏和受壓產生整體或局部挫屈而設計之。在美國 同心斜撐構架之斜撐斷面常用的為圓形、矩(方)形之鋼管、角鋼或是槽形鋼。然而， 國內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。在 北嶺地震之後，對於特殊同心斜撐構架的韌性與消能能力的需求更甚重視，針對SCBF 進行更進一步之研究。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。本研究擬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。參數研究將針對甚為影響斜撐構材非線性行為之細長比、斜撐接合 束制情況與寬厚比等進行研究。預期建立適合國內斜撐構材與接合的非彈性反覆行 為，以期能進行後續之大尺寸實驗與特殊同心斜撐構架之分析。

Special concentrically braced frame (SCBF) is one of the effective earthquake-resisting frames used in the high seismic areas. Unlike the moment-resisting frame, SCBF will behave with inelastic deformation depending on the braces which are designed to yield in axial tension and to buckle, globally or locally, in axial compression. The braces used in the Northern America are usually of sections such as pipe, rectangular tube, angle, or channel. However, the braces used in Taiwan are generally in the form of heavy braces, e.g., H-shaped structural steels or with additional side plates. After the 1994 Northridge earthquake, the demand for the ductility and energy dissipation is seriously expected for the SCBFs and that brings the increase of the research work related to the SCBFs. Due to lack of the experimental results for the heavy braces, the cyclic behavior for heavy braces and their connections is needed to clarify. This research will be conducted using nonlinear finite element analysis to investigate the inelastic cyclic behavior of the braces and connections to gusset plates. Finite element modeling will be validated by comparisons of the analysis results with previous experimental results. The effects of the design parameter, slenderness ratio, width-thickness ratio, and brace end condition, on the nonlinear response of the concentric braces will be studied. Inelastic cyclic behavior of heavy braces is expected for further studying the seismic behavior of the SCBFs