基于负偏心的钢管插板连接的极限承载力

Ultimate Bearing Capacity of Steel Tube-Gusset Plate Connections Considering Negative Eccentricity

研究了主管规格为219×6的、有负偏心作用的1/4加肋钢管插板连接的极限承载力,同时借助有限元法分析了常用主管径厚比下不同长径比、不同负偏心距以及定长径比时主管直径、厚度以及节点板长度等参数对主管极限承载力的影响,在此基础上提出了此类节点极限承载力计算的建议公式.结果表明:在常用的主管径厚比下,负偏心对长径比大于30的主管的承载力是不利的,对长径比小于30的主管的承载力是有利的,这主要是由于长径比大于30时主管整体失稳先于局部屈曲,而长径比小于30时主管局部屈曲起主要控制作用;主管直径、厚度以及节点板长度对承载力影响明显;所得出的建议公式具有一定的适用性.

In this paper,the ultimate bearing capacities of steel tube-gusset plate connections with a tube size of 219×6 and with 1/4 annular ribbed plate subjected to negative eccentric force are analyzed.The investigation is performed for the connections with constant diameter-thickness ratio but variable length-diameter ratio and negative eccentricity,and for the connections with constant length-diameter but variable tube diameter,tube thickness and joint plate length.Then,a formula to calculate the ultimate bearing capacity is proposed.The results indicate that the negative eccentricity is unfavorable to the bearing capacity of steel tube with a length-diameter ratio higher than 30 because the entirety stability of steel tube is the main effect factor.However,the negative eccentricity is favorable when the length-diameter ratio is less than 30 because the local bucking is prior in this situation.It is also indicated that the tube diameter,the tube thickness and the joint plate thickness all affect the ultimate bearing capacity significantly,and that the proposed formula is applicable and feasible for design.