考虑板件相关作用的H形截面分类准则

截面分类是当代钢结构设计规范的重要基础之一，对国内外现行钢结构规范关于H形压弯钢构件截面分类的相关规定进行了综述，对比发现大多数规范都遵循单一板件规则。基于经试验校准的非线性有限元模型，进行了不同翼缘宽厚比、腹板宽厚比及轴压比组配下的H形截面钢构件绕强轴压弯的参数分析，得出不同的宽厚比及轴压比可导致不同的板件破坏模态和极限承载力，进一步证实了板件相关作用对截面分类的影响。提出了基于极限承载力的H形截面钢构件绕强轴压弯下S2、S3、S4和S5级截面分类方法。经与各规范及试验结果的比较，该文截面分类方法更贴近截面的真实承载情况，更加证实了考虑板件相关作用的必要性。

CROSS-SECTION CLASSIFICATION CRITERIA OF STEEL H-SECTIONS CONSIDERING THEPLATE INTERACTION EFFECT

The classification of cross-sections is an important basis for contemporary design specifications of steel structures.The relevant provisions of the current steel structure specifications on the cross-section classification of H-section steel beam–columns were reviewed.It was found that most of the specifications follow the individual plate rule.Based on a verified finite element model,a parametric analysis of H-section members with different combinations of flange and web width-to-thickness ratios as well as different axial force ratios was conducted.Through the simulation results it was observed that different width-to-thickness ratios and axial force ratios could lead to different failure modes and strength.This confirmed the interaction effect of adjacent plates on the classification of cross sections.A classification method for S2,S3,S4 and S5 sections under combined axial force and bending moment around the strong axis of H-section steel members based on the ultimate strength was proposed.Compared with various specifications and experimental results,it is shown that the proposed cross-section classification method represents the response conditions of the plates,which confirms the necessity of considering the interaction effect of adjacent plates.