基于三参数模型的外伸式端板单向螺栓连接梁柱节点极限承载力分析

Analysis of Ultimate Bearing Capacity for Extended Endplate Connections Between Beam-column with Single Direction Bolts Based on Three-parameter Model

目的:分析影响外伸式端板单向螺栓连接节点初始刚度和极限弯矩的主要因素,并拟合出初始刚度和极限弯矩、形状系数的近似计算公式,为装配式钢结构单向螺栓节点连接的研究提供理论参考。方法:通过仿真分析与试验对比建立外伸式端板单向螺栓连接模型,由运行出的弯矩转角曲线得到对初始刚度和极限弯矩影响最大的因素。根据三参数模型及最小二乘法拟合出初始刚度和极限弯矩、形状系数的近似计算公式。结果:在对柱腹板厚度、梁高、端板厚度等参数均等改变后,其数值有明显的增加。柱腹板厚度在均等改变后,初始刚度由2505.6 kN·m/rad增加到3445.5 kN·m/rad,增长率为37.5%。梁的高度由250 mm增加至400 mm,极限弯矩由118.5 kN·m增加到193.4 kN·m,增长率为63.2%。结论:主要影响因素是梁的高度、柱腹板厚度、端板厚度、螺栓直径、端板宽度。并且拟合公式得到的数据值与有限元模型得到的数据对比后,其误差率基本控制在10%以内,验证了拟合公式的正确性。

Objective:To analyze the main factors affecting the initial stiffness and ultimate bending moment of the single direction bolts connection node,and fit the approximate calculation formula of initial stiffness and ultimate bending moment and shape coefficient,and provide theoretical reference for the study of the single direction bolts node connection of prefabricated steel structure.Methods:Based on the comparison of the simulation analysis and test,the factors affect the initial stiffness and ultimate bending moment.According to the three-parameter model and the least square method,the approximate calculation formulas of the initial stiffness,ultimate bending moment and shape factor are fitted.Results:After the parameters of the thickness of the column,beam height and end plate thickness were changed equally,the value increased significantly.For example,after the thickness of the column web was changed equally,the initial stiffness was increased from 2505.6 kN·m/rad to 3445.5 kN·m/rad,with a growth rate of 37.5%.The height of the beam is increased from 250 to 400 mm,and the ultimate bending moment is increased from 118.5 kN·m to 193.4 kN·m,with a growth rate of 63.2%.Conclusion:The main influencing factors are the height of the beam,column wall thickness,end plate thickness,bolt diameter and end plate width.Moreover,after comparing the data value obtained by the fitting formula with the data obtained with the finite element model,the error rate is basically controlled within 10%,which verifies the correctness of the fitting formula.