高強鋼焊接工字形截面壓彎構件局部-整體相關屈曲分析*
申紅俠, 楊春輝
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（西安建筑科技大學土木工程學院， 西安 710055）［摘要］采用有限元法分析了Q460鋼腹板高厚比超限(hw/tw=60，70，80，100，120)的焊接工字形截面壓彎構件的極限承載力，研究了腹板高厚比、翼緣寬厚比、構件長細比和相對偏心率對其屈曲性能的影響，提出了計算Q460鋼壓彎構件局部-整體相關屈曲極限承載力的修正公式。研究表明，有限元法能很好地分析腹板高厚比超限的工字形截面壓彎構件非線性屈曲性能；腹板高厚比增大，極限承載力提高，腹板屈曲后強度保持能力增大，延性增大。相反，翼緣寬厚比增大，構件極限承載力減小，腹板屈曲后強度保持能力減弱，延性降低；長細比增加，構件剛度明顯減小，極限承載力降低，但延性卻增大；相對偏心率增大，彎曲變形起主導作用，跨中撓度急劇增加，而軸力的變化相對變緩。提出的修正公式計算結果與有限元結果吻合很好。［關鍵詞］高強度鋼; 焊接工字形截面; 壓彎構件; 局部-整體相關屈曲; 極限承載力; 有限元分析中圖分類號：TU391，TU323.1，TU311.2文獻標識碼：A文章編號：1002-848X(2013)22-0033-06Analysis of local-overall interaction buckling of high-strength steel welded I-section compression-bending membersShen Hongxia, Yang Chunhui(School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China)Abstract: The ultimate bearing capacity of welded I-section compression-bending members made from high strength steel Q460, with web depth-to-thickness ratios of 60, 70, 80, 100, 120, was analyzed by finite element method. The effect of the web depth-to-thickness ratio, flange width-to-thickness ratio, slenderness ratio and eccentricity ratio on the local-overall interaction buckling behavior was investigated. The modified formulas for predicting the ultimate bearing capacity of high strength steel compression-bending members with large depth-to-thickness ratios were proposed. It shows that the finite element model can analyze the nonlinear bucking behavior of welded I-section compression-bending members with slender web. The ultimate bearing capacity, post-buckling strength reserve and ductility of welded I-section compression-bending members increase with the web depth-to-thickness ratio increasing. On the contrary, the ultimate bearing capacity, post-buckling strength reserve and ductility of the members decrease when the flange width-to-thickness ratio increases. With the increase of the slenderness ratio, the rigidity of the members obviously reduces as well as the ultimate bearing capacity, but the ductility improves. Along with the increase of the eccentricity ratio, the flexural deformation dominates the interaction and the deflection at the mid-span increases rapidly, while the axial force changes slowly. The proposed modified formulas are in good agreement with the numerical results.Keywords: high strength steel; welded I-section; compression-bending member; local-overall interaction buckling; ultimate bearing capacity; finite element analysis*陜西省自然科學基礎研究計劃資助項目（2013JM7008），陜西省教育廳專項科研計劃資助項目（2013JK0978）。作者簡介：申紅俠，博士，副教授，碩士生導師，Email: shenhongxia88@126.com。參考文獻［1］USAMI TSUTOMU, FUKUMOTO YUHSHI. Welded box compression members［J］. Journal of the Structural Engineering, 1984, 110(10):2457-2470.［2］USAMI TSUTOMU, FUKUMOTO YUHSHI. Local and overall buckling of welded box columns［J］. Journal of the Structural Division, 1982, 108(ST3):525-542.［3］陳紹蕃.焊接薄壁箱形截面軸心壓桿的承載力計算［J］. 建筑鋼結構進展, 2009, 11(6): 1-7.［4］SHEN HONGXIA. Ultimate capacity of welded box section columns with slender plate elements［J］. Steel and Composite Structures, 2012, 13(1): 15-33.［5］申紅俠. 高強度鋼焊接方形截面軸心受壓構件的局部和整體相關屈曲［J］. 工程力學, 2012, 29(7): 221-227.［6］申紅俠. 寬厚比超限的高強鋼方形截面軸心受壓構件的極限承載力［J］. 建筑結構, 2012, 42(11): 119-122.［7］GB 50017—2003 鋼結構設計規(guī)范［S］. 北京: 中國計劃出版社, 2003.［8］BAN HUIYONG，SHI GANG，SHI YONGJIU，et al. Overall buckling behavior of 460MPa high strength steel columns: Experimental investigation and design method［J］. Journal of Constructional Steel Research, 2012, 74:140-150.［9］顧強. 腹板寬厚比超限時I形截面偏壓桿平面內(nèi)的承載力［D］. 西安：西安冶金建筑學院，1988.［10］顏衛(wèi)亨，張興武. 寬腹板I形截面偏壓構件平面內(nèi)承載力的探討［J］.四川建筑科學研究，1996(2): 7-8,18.
