高强钢焊接工字形截面压弯构件局部-整体相关屈曲分析  

Analysis of local-overall interaction buckling of high-strength steel welded I-section compression-bending members

作　　者：申红侠[1] 杨春辉[1] 

机构地区：[1]西安建筑科技大学土木工程学院,西安710055

出　　处：《建筑结构》2013年第22期33-38,共6页Building Structure

基　　金：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)

摘　　要：采用有限元法分析了Q460钢腹板高厚比超限(h w/t w=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。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,postbuckling 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.

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 

分 类 号：TU391[建筑科学—结构工程] TU323.1