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现有组装式货架结构的冷弯薄壁开口多卷边柱截面较复杂,加劲高度、侧边高度、斜卷边坡角等参数的变化均对截面加工成形的精度有较大影响。本文基于直接强度法,结合参数化有限元分析,对比研究多卷边柱截面的有限元及使用中国规范、北美规范的计算结果。研究结果表明:对于冷弯薄壁开口多卷边柱,短柱失稳以畸变屈曲为主、辅以局部屈曲,长柱失稳以弯扭失稳为主;对于短柱及中长柱,有限元分析结果与两种规范均吻合良好,长柱则不够理想,相对于有限元结果,中国规范计算值偏低22.9%,北美规范计算值偏低17.0%,两种规范计算值均偏保守,此结果可以为该类截面规范公式修订提供参考。综合考虑截面性能及工艺要求,提出了一种与原有截面S0相比既能提高加工精度又能提高稳定承载力的截面形式S4。
The cross section of the multi-turn column with cold-formed and thin-walled openings in the existing assembled shelf structure is quite complicated. The changes of the parameters such as stiffener height, side height and bevel angle have a great influence on the precision of cross-section forming. Based on the direct strength method and the parametric finite element analysis, the finite element method for the cross-section of the multi-turn side columns is compared and the calculation results using the Chinese norms and North American norms are compared. The results show that the buckling of the short column is dominated by the distorted buckling, and the buckling of the long column is mainly buckling and twisting. For the short columns and the long column, The results of the finite element analysis agree well with the two specifications, but the long columns are not ideal enough. Compared with the finite element results, the calculated values in China are 22.9% lower than those in the North American standard and 17.0% lower in the North American codes, both calculated conservatively This result can provide a reference for the revision of the formula of this kind of cross-section. Considering the cross-sectional performance and technological requirements, a new cross-section S4 is proposed, which can improve the machining accuracy and increase the stable bearing capacity compared with the original cross-section S0.