带槽口缺陷的圆钢管短柱轴压性能试验

Experimental study on compressive behavior of circular steel stub columns with notch defects

对51根带有在圆钢管切割工艺中产生的槽口缺陷的圆钢管短柱进行轴压性能试验研究.研究结果表明:对于带槽口缺陷的圆钢管短柱,管壁较厚的在槽口缺陷处只会产生凸起屈曲,而管壁较薄的在槽口缺陷处会有凸起屈曲和凹陷屈曲两种破坏模式.槽口缺陷的存在既会小概率使得圆钢管短柱有更明显的屈服平台,形成双峰曲线,也会普遍减小圆钢管短柱的初始刚度和延性系数;槽口缺陷高度在0.5倍的壁厚范围内对初始刚度、延性系数和极限承载力的影响微乎其微;钢管管壁越薄,缺陷对极限承载力的影响愈加显著,其极限承载力下降幅值更大.最后,提出槽口缺陷影响系数并给出考虑槽口缺陷的圆钢管短柱极限承载力计算公式.

An experimental study on the axial compression performance of 51 short circular steel tube columns with notch defects generated in the cutting process was performed.The results of the study showed that,circular steel stub columns with large wall thickness will only show convex buckling at the notch defects;circular steel stub columns with small wall thickness will have convexities at the notch defects.The notch defect made circular steel stub columns having a more obvious yield platform,forming a double-peak curve.The existence of notch defects will generally reduce the initial stiffness and ductility coefficient of circular steel stub columns.The notch defect height within 0.5 times the wall thickness had little effect on the initial stiffness,ductility coefficient,and ultimate bearing capacity.The thinner the wall of the steel pipe,the more significant the impact of the defect on the ultimate bearing capacity,and the greater the decrease in the ultimate bearing capacity.Finally,the paper proposed the influence factor of the notch defect and gave the formula for calculating the ultimate bearing capacity of circular steel stub columns considering the notch defect.