考虑板件相关作用的H形截面压弯钢构件抗弯承载力

对H形截面钢构件绕强轴压弯的极限抗弯性能展开研究。基于经实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形截面钢构件的单调压弯全过程的参数分析,并对破坏模式进行了机理分析。研究表明,翼缘与腹板存在明显的相关作用,而板件屈曲形式决定了极限状态的应力分布形式,因此计算极限承载力时应考虑板件相关作用。以极限状态的应力分布特点为基础,提出了考虑板件塑性阶段屈曲相关作用的有效塑性宽度法计算截面的极限抗弯承载力。经与实验及有限元极限承载力的比较,显示该方法能够准确预测H形截面压弯构件的极限承载力。

MOMENT RESISTANCE OF H-SECTION STEEL BEAM-COLUMNS CONSIDERING THE INTERACTIVE EFFECT OF PLATE ELEMENTS

The ultimate performance of H-sectional steel beam-columns bent about the strong-axis was thoroughly investigated. Based on a verified finite element model, parametric analysis of H-sectional members with different combinations of flange and web width-to-thickness ratios as well as different axial force rations was conducted, and the failure mechanism was derived from the stress development curves. It was found that in the ultimate stage, the stress distribution was significantly affected by the local buckling mode, which turned out to depend on the flange-web interaction. Thus, it is necessary to take the flange-web interactive effect into consideration when calculating the ultimate strength. Finally, based on the stress distribution property in the ultimate state, a calculation approach to calculating the ultimate moment denoted as “effective-plastic-width method” was proposed. This approach was validated through comparison with experimental results and FEM analysis.