K型圆钢管搭接节点极限承载力研究

钢管搭接节点是一种在空间结构中常见的节点形式,本文对平面K型圆钢管搭接节点的极限承载力进行了非线性有限元分析。结果表明:随着支主管直径比、支主管厚度比、主管径厚比和搭接率的变化,节点发生支管轴向屈曲破坏、支管局部屈曲破坏和支主管联合屈曲破坏三种破坏模式。在支主管厚度比分别为0.4、0.7和1.0,且搭接率为20%～60%时,与相应的间隙节点极限承载力的比值分别在0.95～1.06、0.95～1.61和1.17～1.27之间;与规范公式承载力计算结果的比值分别为小于1.0、在0.99～1.51和1.33～2.17之间。研究表明,圆钢管搭接节点的受力性能与有间隙的相贯节点有明显的差别,设计计算时应分别考虑。

The study of ultimate bearing capacity of overlapped CHS K-joints

Overlapped tubular joints is one of fundamental joint configurations used in the spacial structures,nonlinear finite-element analysis of planar ov erlapped circular hollow section(CHS) K-joints was carried out in this paper. T he result showed that three failure modes of the joints are observed with differ ent nondimensional joint parameters a(diameter ratio of branch to chord),?( ratio of chord diameter to its thickness),?(thickness ratio of branch to chor d )and Ov(overlap ratio). These failure modes are branch failure,branch loca l buckling failure and combined branch local buckling and chord bending failure. When the ratio ?varies from 0.4 to 1.0 and overlap amount Ov varies from 20%t o 60%,the ultimate strength of overlap joints is 0.95-1.27 times larger than that of gap joints. Correspondingly,the ultimate strength of overlap joints is 0.99-2.17 times larger than the calculated results of design formulae. The stud y reveals that there is a significant difference in behavior between overlap joi nts and gap joints which needs to be considered in design and calculation respec tively.