高强钢焊接工字形截面压弯构件局部-整体相关屈曲分析*
- 摘 要
-
（西安建筑科技大学土木工程学院， 西安 710055）［摘要］采用有限元法分析了Q460钢腹板高厚比超限(hw/tw=60，70，80，100，120)的焊接工字形截面压弯构件的极限承载力，研究了腹板高厚比、翼缘宽厚比、构件长细比和相对偏心率对其屈曲性能的影响，提出了计算Q460钢压弯构件局部-整体相关屈曲极限承载力的修正公式。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压弯构件非线性屈曲性能；腹板高厚比增大，极限承载力提高，腹板屈曲后强度保持能力增大，延性增大。相反，翼缘宽厚比增大，构件极限承载力减小，腹板屈曲后强度保持能力减弱，延性降低；长细比增加，构件刚度明显减小，极限承载力降低，但延性却增大；相对偏心率增大，弯曲变形起主导作用，跨中挠度急剧增加，而轴力的变化相对变缓。提出的修正公式计算结果与有限元结果吻合很好。［关键词］高强度钢; 焊接工字形截面; 压弯构件; 局部-整体相关屈曲; 极限承载力; 有限元分析中图分类号：TU391，TU323.1，TU311.2文献标识码：A文章编号：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*陕西省自然科学基础研究计划资助项目（2013JM7008），陕西省教育厅专项科研计划资助项目（2013JK0978）。作者简介：申红侠，博士，副教授，硕士生导师，Email: shenhongxia88@126.com。参考文献［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］陈绍蕃.焊接薄壁箱形截面轴心压杆的承载力计算［J］. 建筑钢结构进展, 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］申红侠. 高强度钢焊接方形截面轴心受压构件的局部和整体相关屈曲［J］. 工程力学, 2012, 29(7): 221-227.［6］申红侠. 宽厚比超限的高强钢方形截面轴心受压构件的极限承载力［J］. 建筑结构, 2012, 42(11): 119-122.［7］GB 50017—2003 钢结构设计规范［S］. 北京: 中国计划出版社, 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］顾强. 腹板宽厚比超限时I形截面偏压杆平面内的承载力［D］. 西安：西安冶金建筑学院，1988.［10］颜卫亨，张兴武. 宽腹板I形截面偏压构件平面内承载力的探讨［J］.四川建筑科学研究，1996(2): 7-8,18.
