内置型钢增强钢管约束钢筋混凝土柱节点抗震性能研究

Seismic Performance of Steel Tube⁃reinforced Concrete Column Joints Embedded with Built⁃in Section Steel

采用钢管对传统RC柱进行约束,形成的钢管约束钢筋混凝土(STRC)柱具有优越的承载能力和耗能性能。但在应用于框架节点设计时,节点区域仍采用普通RC柱节点构造,可能导致节点处没有钢管约束而成为薄弱点,节点处易发生破坏。针对钢管约束钢筋混凝土(STRC)柱节点抗震性能薄弱的现状,提出采用内置型钢短柱进行增强。基于ABAQUS工作平台对具有相同构造形式的节点试件建立有限元模型,将数值计算所得破坏形态、滞回曲线和型钢应力与试验结果进行对比,两者吻合较好,在此基础上探讨内置型钢长度和轴压比对节点抗震性能的影响。结果表明:随着内置型钢长度增加,试件的承载力、极限位移和延性均有不同程度的提升,轴压比对试件受力性能影响较小。通过进一步分析试件的破坏机制、型钢抗弯性能和耗能能力,提出满足节点抗震性能需求的内置型钢长度建议取值。

Steel tubes are used to constrain traditional reinforced concrete(RC)columns,forming steel tube-reinforced concrete(STRC)columns,which exhibit superior load-bearing capacity and energy dissipation performance.However,when applied to frame joint design,the joint area still adopts ordi-nary RC column node structures,potentially leading to weak points without steel tube constraints,making the joint area prone to damage.To address the issue of weak seismic performance at the joints of STRC columns,an enhancement method using built-in short steel columns was proposed.Finite el-ement models of joint specimens with the same construction form were established based on the ABAQUS working platform and the numerical results for failure modes,hysteresis curves,and steel stress were compared with test results,showing good agreement.On this basis,the influence of the built-in steel length and axial compression ratio on the seismic performance of the joints was discussed.The results indicated that with the increasing length of the built-in steel,the load-bearing capacity,ul-timate displacement,and ductility of the specimens were improved to varying degrees,while the axial compression ratio had a minor effect on the mechanical properties of the specimens.Through further analysis of the failure mechanism,bending resistance,and energy dissipation capacity of the built-in section steel,suggestions for the optimal length of the built-in section steel to meet the seismic perfor-mance requirements of the joint were proposed.