壓彎構件彎扭屈曲穩(wěn)定系數(shù)φb的簡化計算
陳紹蕃
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（西安建筑科技大學結構工程與抗震教育部重點實驗室， 西安 710055）［摘要］鑒于受彎構件整體穩(wěn)定計算比較復雜，現(xiàn)行《鋼結構設計規(guī)范》（GB 50017—2003）除給出了正規(guī)穩(wěn)定系數(shù)φb的計算公式外，還給出了此系數(shù)的近似計算公式，后者主要用于壓彎構件彎扭屈曲的計算。新修訂的《鋼結構設計規(guī)范》（送審稿）對梁的整體穩(wěn)定計算做出較大修改，但計算依然較為復雜，仍然需要新的簡化公式與之配合。經過分析和比較，推薦了工形截面和T形截面構件受彎屈曲時穩(wěn)定系數(shù)φb的簡化公式。為了適用于壓彎構件，推演公式時緊密結合這類構件的具體情況：工形截面著眼于框架柱，T形截面著眼于承受節(jié)間荷載的桁架受壓弦桿。推薦的公式具有較好的精確度，但不宜廣泛用于一般受彎構件。［關鍵詞］梁; 壓彎構件; 彎扭屈曲; 穩(wěn)定系數(shù); 簡化公式中圖分類號：TU318+.1 文獻標識碼：A 文章編號：1002-848X(2014)21-0001-06Simplified calculation of the stability coefficient φb for flexuraltorsional buckling of beam-columnsChen Shaofan(Key Laboratory of Structural Engineering and Earthquake Resistance, Ministry of Education, Xi’an University of Architecture and Technology, Xi’an 710055, China)Abstract:In the current Code for design of steel structures (GB 50017—2003), besides regular formulae of stability coefficient φb for flexural members, approximate formulae of this coefficient are also given, because of the complicity of the former. The latter is mainly used in the calculation of flexural torsional buckling of beam-columns. In the final draft of the revised version of Code for design of steel structures, the overall stability calculation of beams has been changed to a large extent, but is still rather complicate, so that new simplified formulae are again in need. Based on analysis and comparison, simplified stability coefficient formulae for φb were suggested for I-section and T-section members under bending moment. In order to be suited to beam-columns, the derivation of these formulae are closely related to the specific situation of those members: the I-section members focusing on columns of frames, and T-section members on the compressive chords of trusses subject to transverse loading between panel points. The suggested formulae have good accuracy, but are not recommended for comprehensive use to flexural members in general.Keywords:beam; beam-column; flexural torsional buckling; stability coefficient; simplified formula作者簡介：陳紹蕃，教授，Email: chensf12@163.com, sumingzhou@163.com。參考文獻［1］陳紹蕃. 雙軸對稱工形截面無支撐簡支梁的整體穩(wěn)定［J］. 鋼結構, 2008, 23(8): 6-13.［2］陳紹蕃. 鋼結構穩(wěn)定設計指南［M］. 3版.北京：中國建筑工業(yè)出版社, 2013: 145.［3］童根樹. 鋼梁穩(wěn)定性再研究: 國內近年的研究成果和建議（IV）［J］. 工業(yè)建筑, 2014, 44(4): 146-151.［4］陳紹蕃. 鋼結構開口截面偏心壓桿在彎矩作用平面外的穩(wěn)定系數(shù)［G］//設計標準規(guī)范工作動態(tài)專輯（鋼結構部分）.冶金建筑,1977: 89-101.［5］陳紹蕃. 單軸對稱工形截面無支撐簡支梁的穩(wěn)定承載能力［J］. 鋼結構, 2008, 23(8): 14-19.［6］陳紹蕃, 顧強. 鋼結構上冊：鋼結構基礎［M］. 2版.北京: 中國建筑工業(yè)出版社, 2011: 114-115.［7］ANSI/AISC 360-10 Specification for structural steel buildings［S］. Chicago: American Institute of Steel Construction, 2010.［8］陳紹蕃. 角鋼、剖分T形鋼壓桿的彎扭屈曲（1）［J］. 鋼結構, 2000, 15(4): 47-49.
