螺钉间距对冷弯薄壁双肢拼合箱形截面短柱承载力性能的影响

EFFECT OF SCREW SPACING ON BEARING CAPACITY OF COLD-FORMED THIN-WALLED STEEL WITH BUILT-UP BOX SECTION SHORT COLUMNS

为了研究螺钉间距对冷弯薄壁型钢(CFS)拼合箱形截面短柱承载力的影响,基于已有的试验结果,利用ABAQUS有限元软件建立经验证为合理可靠的有限元模型,设计4种截面尺寸双肢拼合箱形短柱进行变螺钉参数分析。结果表明:当螺钉间距小于C形基本构件局部屈曲半波长度λ_c时,随着螺钉间距的增大,拼合箱形截面短柱极限承载力呈下降趋势;当螺钉间距等于λ_c时,承载能力略微增大;当螺钉间距大于λ_c时,随着螺钉间距的增大,拼合箱形截面短柱极限承载力呈下降趋势。另外,CFS拼合箱形截面短柱承载力符合"1+1"约等于2的原则,即相对于单肢截面短柱,拼合箱形截面短柱承载力增强不明显。

Based on the existing experimental results, the paper built a reasonable and reliable finite element model by the ABAQUS finite element software, and parameter analysis were conducted to study the effect of screw spacing on bearing capacity of the cold-formed short built-up box section column with four kinds of cross-sectional dimensions. The results showed that when the screw spacing was less than the local buckling half-wave length of the C-section basic member λ_c, the ultimate bearing capacity of short built-up box section column tended to decrease with the increase of the screw spacing;when the screw spacing was equal to λ_c, the bearing capacity slightly increased;when the screw spacing was greater than λ_c, the ultimate bearing capacity of built-up box section columns decreased as the increase of the screw spacing. In addition,the ultimate bearing capacity for the short built-up box section column conformed to the principle that "1+1" was approximately equal to 2. Compared with the single section column, the bearing capacity of the short built-up box section column was not significantly enhanced.