带垫板的双肢冷弯C型钢框架抗震性能研究

针对带垫板的双肢冷弯C型钢框架抗震性能问题，选取垫板厚度、框架跨度、C型钢厚度、C型钢翼缘宽厚比和C型钢腹板高厚比等作为研究参数，采用拟静力试验和有限元方法分析了14个单层单跨框架，得到了该类框架的滞回曲线和骨架曲线，分析了框架的破坏模式和抗震性能。结果表明:框架先发生梁端和柱脚的局部屈曲，最终平面内失稳破坏。垫板厚度在保证强节点的前提下，对框架的承载力和抗震性能影响很小。C型钢截面参数变大可以提高框架承载力，增加C型钢厚度可以提高框架延性。该类框架的承载力退化稳定，具有较好的延性和耗能能力，抗震性能好。建议设计框架梁柱线刚度比不宜低于0.4。

SEISMIC BEHAVIOR OF COLD-FORMED DOUBLE C STEEL FRAMES WITH GUSSET PLATES

This paper presents experiments and finite element analyses of seismic behavior of 14 single layer and single span frames of cold-formed double C steel with gusset plates. The effects of gusset plate thickness, frame span, C steel thickness, C steel flange width-thickness ratio, and C steel web depth-thickness ratio on the seismic behavior of the frames were discussed. Hysteretic curves and skeleton curves were presented, and the failure mode and seismic behavior were analyzed. It is noted that the frame showed in-plane instability with local buckling of the beam ends and column bases. Ensuring strong nodes, the plate thickness had less influence on the bearing capacity and seismic behavior. Increasing section parameters of the C steel, the bearing capacity of the frame increased accordingly. As the C steel thickness increased, the ductility of the frame increased. This frame showed stable bearing capacity degradation, and good ductility, energy dissipation capacity, and seismic behavior. It is proposed that the stiffness ratio of column to beam is no less than 0.4.