钢管混凝土边柱与组合梁端板连接的抗震试验研究

Experimental study on seismic performance of endplate connections between CFST external columns and composite beams

为研究地震荷载作用下钢管混凝土柱与钢-混凝土组合梁端板连接的受力性能和破坏机理,进行4榀带楼板半刚性钢管混凝土组合框架端板连接节点的低周反复荷载试验。试件为边柱节点,试验参数为柱截面类型和端板类型。详细考察试验全过程和试件破坏模式,分析组合节点的滞回曲线、骨架曲线及特征值、强度和刚度退化规律、耗能能力等。根据现有规范评价节点的刚性和延性。研究表明,端板类型、柱截面类型和螺栓锚固构造对组合节点的承载力和刚度有明显影响;钢管混凝土边柱与钢-混凝土组合梁端板连接节点为半刚性连接、部分强度节点;此类新型组合节点具有良好的延性和耗能能力,连接构造安全可靠,满足现有抗震设计要求,可以在组合框架结构中应用。

To investigate the mechanical properties and failure mechanism of the endplate connections between Concrete-Filled Steel Tubular columns （CFST） and steel-concrete composite beams, an experimental study on four specimens of the endplate joints for semi-rigid CFST composite frame with concrete floorslab was conducted under low- cycle loading. All specimens are external column joints, and the column cross-section type and the endplate type are test parameters. The entire test process of all specimens and the failure mode were investigated, and the hysteresis curves, envelope curves and characteristic value, degradation regulation of strength and stiffness, and energy dissipation were also carefully observed. The test results show that the endplate type, the column cross-section type and the anchorage of blind bolts may affect the moment capacities and initial stiffness of composite joints. The endplate joints between CFST external columns and composite beams appear to be semi-rigid and partial strength joints. The novel composite joint possesses good ductility and energy dissipation capacity, reliable and safe performance in connection, so that it may satisfy the seismic design requirement and be used in composite structures.