三肢冷弯薄壁型钢拼合双腔箱形柱受压性能试验研究与数值分析

Experimental study and numerical analysis on compressive behavior of three-limb built-up cold-formed steel columns with double box section

对12根三肢冷弯薄壁型钢拼合双腔箱形柱分别进行了轴压、偏压试验和数值模拟分析.通过试验研究,得到了各试件的荷载-位移、荷载-应变曲线以及最大承载力,并分析了屈曲模式和破坏特征.采用有限元软件ABAQUS分析了双腔箱形柱的长细比变化、截面腹板的高厚比变化、荷载偏心方向和偏心距参数对拼合双腔箱形柱受压性能的影响.结果表明,LT-A(长柱)和MT-A(中长柱)组试件的最终破坏模式为整体弯曲屈曲破坏,个别MT-A组试件破坏位置发生在柱端,其余均在柱中.试件的轴压最大承载力均随试件长细比的增大而逐渐减小.试件轴压最大承载力随截面腹板高厚比的减小而增大;偏压试件的最大承载力随着偏心距的增加而降低.

Experimental study and numerical simulation on 12 three-limb built-up columns with double boxes section were carried out to study the compressive behavior under axial and eccentric loading. The load-displacement curves, the load-strain curves and the maximum bearing capacity of the specimens were obtained through the experimental study. The buckling modes and the failure characteristics were analyzed. The finite element software ABAQUS was used to analyze the influence of the slenderness ratio of the columns, the web height to thickness ratio of the section, the eccentricity and the direction of the loading on the compressive behavior of the built-up cold-formed steel columns with double box section. The results show that the final failure mode of the LT-A(long length columns) and MT-A(middle length columns) group specimens are overall flexural buckling damage. Most of the damage locations are in the mid-height of columns, except for the individual specimens of MT-A group. The maximum bearing capacity of the specimens decreases with the increase of the slenderness ratio of the columns. The maximum bearing capacity of the specimens increases with the decrease of the height thickness ratio of the web. The maximum bearing capacity of the specimens under eccentric compression decreases with the increase of the eccentricity.