十字形钢管混凝土柱-H形钢梁框架节点抗震性能研究

为了研究十字形钢管混凝土柱-H形钢梁框架中节点的抗震性能和破坏机理，进行了6个缩尺比为1∶2的节点拟静力试验。观察节点的损伤过程及破坏模式，分析柱端荷载-位移滞回曲线、节点核心区剪力-剪切变形曲线、层间位移角组成、耗能能力及应力分布。采用ABAQUS软件建立钢管混凝土异形柱-H形钢梁框架节点的有限元分析模型，分析结果与试验结果吻合良好，并对节点核心区受剪承载力和节点刚度进行参数分析。研究结果表明：节点的滞回曲线饱满，延性系数介于2.63～4.45之间，等效黏滞阻尼系数介于0.202～0.241之间，节点域的变形和耗能能力较强；建立的有限元分析模型可用于模拟节点的抗震性能，有限元参数分析结果表明增加节点区钢管厚度可以明显提高核心区受剪承载力，增加竖向肋板尺寸可以有效提高节点刚度。为保证竖向肋板节点达到刚性节点要求，建议柱钢板宽厚比不大于30；竖向肋板翼缘外高度、翼缘内高度以及竖向肋板与梁翼缘连接长度分别不应小于梁翼缘宽度的30%、15%和150%；竖向肋板厚度不应小于梁翼缘厚度。

Research on seismic behavior of cruciform special-shaped CFST column to H-section steel beam joint

To investigate the seismic behavior and failure mechanism of interior joint between concrete-filled steel tubular (CFST) column and H-section steel beam, quasi-static tests were carried out on six specimens with scale ratio of 1∶2. The damage process and failure mode were observed, and the load-displacement hysteretic curves, the joint shear deformation, inter-story drift ratio composition, energy dissipation capacity and strain distribution were analyzed. A finite element (FE) model using ABAQUS software was established and verified with the experimental results. Furthermore, a parametric analysis with the FE model was conducted to investigate the influences on the joint shear capacity and joint stiffness. The results show that the hysteretic curve of the joint is plump. The ductility coefficient is between 2.63-4.45. The equivalent viscous damping coefficient is between 0.202-0.241. The deformation and energy dissipation capacity of the joint panel zone are relatively favorable. The finite element analysis model can be used to simulate the seismic performance of the joint. Numerical results show that increasing the joint steel tube thickness can significantly improve the shear resistance of the joint panel zone, and increasing the vertical rib dimensions can effectively improve the joint stiffness. To meet the rigid joint requirements of vertical rib joints, it is suggested that the width thickness ratio of column steel plate should not be greater than 30. The outer height of the vertical rib, the inner height, the connection length between the vertical rib and the beam flange should not be less than 30%, 15% and 150% of the beam flange width, respectively. The thickness of the vertical rib should not be less than the thickness of the beam flange.