卷焊圆管、方管轴压杆的脆性屈曲

Brittle buckling of cold-formed welded steel tube struts under axial load

钢管截面构件受压时为脆性屈曲,可靠指标β与普通压杆理应有所不同,但目前国内有关设计规范(程)对此都没有反映。本文采用弹塑性梁柱理论、数值积分法计算了卷焊圆管、方管截面轴压杆完整的荷载-位移曲线,分析了纵向焊接残余应力、初弯曲、板件宽厚比(径厚比)对钢管压杆屈曲及屈曲后性能的影响,提出了圆管、方管截面轴压杆稳定承载力计算方法。

The structural safety factor of axially loaded welded steel tube struts failed by brittle buckling should be different from ordinary steel columns, but all of the design codes in China have not dealt with this problem. Based on the inelastic beam-column theory, this paper calculated the load-deflection curves of cold-formed welded circular and square hollow section struts by numerical integration technique. Taking the effects of residual stresses,initial geometric imperfections and component plate slenderness into consideration, the post-ultimate behavior of brittle buckling struts are assessed, let the reliability index β=3.7 for brittle buckling struts, the design recommendations are presented.