T形截面翼缘和腹板宽厚比的相关关系

Interaction Relation Between the Limiting Ratios of Flange and Web in T-Section

研究了轴心受压T形截面考虑翼缘和腹板相互约束的截面局部屈曲,给出了局部屈曲临界应力的公式。将确定板件分类等级的方法应用到截面分类上,以腹板和翼缘宽厚比相关关系的形式给出了4类截面S1,S2,S3和S4的分类标准。观察曲线形状发现,曲线可分成传统分类区和扩展分类区。在传统分类区,翼缘和腹板进行独立分类;在扩展分类区,腹板的宽厚比限值可以放宽,但是翼缘的宽厚比限值必须更严,以考虑翼缘对腹板的约束作用带来的对翼缘本身的削弱。为此对4类截面提出了宽厚比限值的计算公式,以供规范编修时参考。

Buckling of T-Sections under compression is studied analytically considering the interaction between flange and web.Formulas for the critical stress of the cross-section are presented.Extending the classification philosophy of steel plates to steel cross-sections,the paper obtained the interaction curves between the limiting values of the width-to-thickness ratios of flanges and webs for 4 classes(S1,S2,S3,S4)of the T-section.Based on the interaction curves,it is revealed that the classifications are composed of two regions:one is the traditional,in which flange and web are classified independently;the other is the extended region for which the width-to-thickness ratio of the web is relaxed and correspondingly the flange’s width-to-thickness ratio is more stringent to reflect the weakening effect to the flange itself due to providing restraint to the web.For 4 classes of T-section,the limiting values are presented for possible references of codification.