圆钢管KK′X型节点性能的参数分析与设计公式

Parametric Analysis and Design Formulas for Circular Hollow Section KK′X Joints

摘要:

采用经试验验证的有限元模型，对空间KK′X型圆钢管间隙节点极限承载力进行各类参数分析。研究揭示：τ_K和τ_X对节点极限承载力影响较小，其余几何参数影响较大；随着X支管轴力增大，K支管在节点处的极限承载力显著降低；主管轴压应力对节点极限承载力不利，主管轴拉应力对节点极限承载力影响很小。在钢结构设计标准关于平面K型节点承载力计算公式的基础上，提出了采用几何调整系数μ_KKX和支管轴力比影响系数ψ_m表达的基于主管塑性破坏、轴力作用下的空间KK′X型节点极限承载力计算公式，其准确性得到了有限元和试验结果的验证。按照钢结构设计标准采用的校正法，最终提出了空间KK′X型圆钢管间隙节点的承载力设计公式，为该种复杂管节点的工程应用提供了设计指南。

Abstract:

Parametric analysis for the ultimate bearing capacity （UBC） of multiplanar KK′X gap joints in circular hollow section （CHS） trusses is conducted using the finite element （FE） model validated by tests. The study reveals that τ_K and τ_X have minimal impact on the UBC of the joints， whereas other geometric parameters exert a greater influence. UBC of K-brace significantly decreases with the increase of axial force in the X-brace. The axial compressive force in the chord member adversely affects the UBC， while axial tension has little impact. Based on the calculation formulas for UBC of uniplanar K-joints in design standard of steel structures， the formula for UBC of multiplanar KK′X joints subjected to axial force on K-brace with chord plasticization failure is proposed by means of geometric adjustment coefficient μ_KKX and influence coefficient ψ_m considering the ratio of axial force between braces. The accuracy of this formula has been validated by FE analysis and experimental data. Using the calibration method prescribed in design standard of steel structures， a design formula for UBC of multiplanar CHS KK′X joints is finally recommended， providing a practical design guideline for the engineering application of this type of complicated tubular joints.