焊接栓钉型钢混凝土柱压-弯-剪-扭滞回性能试验研究

为了研究压-弯-剪-扭复合受力焊接栓钉型钢混凝土柱的滞回性能，通过研发的试验装置，对设计的9个试件进行恒定轴压力下低周反复弯-剪-扭的加载试验，考虑了栓钉位置、栓钉间距和栓钉长度等3个变化参数。通过试验观察了试件的受力破坏过程及形态，获取其弯矩-位移和扭矩-扭率滞回曲线，并分析了试件破坏形态、滞回曲线、刚度退化、能量耗散、延性等抗震性能指标。结果表明：恒定轴压力反复弯-剪-扭作用下，型钢混凝土试件表现为以弯曲破坏为主、伴随扭转斜裂缝的弯扭型破坏形态；弯矩-位移滞回曲线呈梭形，滞回环饱满，而扭矩-扭转角滞回曲线则呈反S或Z形，滞回曲线不饱满；扭矩作用下，型钢混凝土柱的延性变差；通过焊接栓钉可提高其延性，栓钉间距越小延性越好，当型钢翼缘和腹板交错焊接栓钉时，更有利于提高构件的抗震性能。

Experimental investigation on hysteretic behavior of welded stud steel reinforced concrete columns subjected to constant axial compression and cycled flexure-shear-torsion

To investigate the hysteretic behavior of welded stud steel reinforced concrete columns subjected to constant axial compression and cycled flexure-shear-torsion, a set of test devices were designed, and nine specimens were prepared for the experimental study. Three parameters, i.e. the welded stud location, spacing and the length of stud were considered in test. The cracks develop progress, failure modes, the flexure-displacement hysteric curves, and torsion-torsion ratio hysteretic curves of welded stub steel reinforced concrete columns under constant axial compression and cycled flexure-shear- torsion were obtained. The effects of these parameters on seismic indexes were discussed, such as failure mode, hysteretic behavior, stiffness degradation, ductility and energy dissipation capacity, and so on. The results show that the failure modes of specimens are torsion-bending failure with torsion cracks, which mainly based on flexural failure. The flexure-displacement hysteretic curves are plump like spindle. The torsion-torsion angle hysteretic curves look like S or Z-shape, which are not so plump. The ductility of specimens weakens under the action of torsion. Welded stud can effectively improve the ductility of the steel reinforced concrete columns, and the smaller the stud spacing, the better the ductility. Staggered welding studs on web and flanges can obviously improve the seismic behavior of specimens.