受拉T形连接件高强螺栓受力性能研究

Research on mechanical property of high-strength bolts in tensioned T-stub connections

对钢结构梁柱高强螺栓连接节点的T形连接件的受拉螺栓性能进行研究。改变T形连接件端板翼缘厚度、螺栓位置、螺栓直径和强度等级,同时考虑螺栓接触力偏心,对高强螺栓连接T形连接件进行受拉试验,研究弯矩对螺栓受力性能的影响。试验结果表明:随着T形连接件端板翼缘厚度降低、螺栓直径和强度等级减小以及螺栓内、外翼缘长比值远离数值1,弯曲应力占螺栓截面最大拉应力的比值上升,截面弯矩不能被忽略。采用有限元软件进行分析,分析结果和试验结果吻合较好。弯矩作用形成的拉应力最大可达总拉应力的25%。采用最小二乘法进行拟合,简化受拉T形连接件模型,得到了螺栓的弯矩和撬力计算式,可为钢结构梁柱高强螺栓连接节点设计提供参考。

The tensioned bolts in high-strength bolted beam-to-column connection was simplified as the T-stub connection in order to study the mechanical performance. Tensile tests on the T-stub connection with high strength bolts were conducted considering the thickness of endplate, threaded hole position, bolt diameter and strength grade, as well as the eccentric contact force to investigate the influence of moment. The result shows that with the decrease of endplate thickness, bolt diameter and strength grade, and the internal-external flange length ratio deviates from the constant value of 1, the ratio of bending stress to the total tensile stress of the bolt section increase, and the bending moment can not be ignored. The finite element analysis results are in good agreement with experimental results. The ratio of tensile stress caused by bending moment to the total tensile stress can be up to 25%. The least square method was used for the fitting analysis to obtain calculation formulas for the moment and prying force of bolts based on the simplified T-stub model. The research result could be the reference for the design of high-strength bolts in beam to column connection of steel structure. © 2016, Editorial Office of Journal of Building Structures. All right reserved.