配钢率对型钢混凝土异形柱抗震性能的影响分析

设计了16个型钢混凝土异形柱试件,包括L形柱、沿腹板加载的T形柱、沿翼缘加载的T形柱和十形柱各4个,采用试验研究和有限元模拟相结合的方法分析配钢率对试件抗震性能的影响,得到了试件的破坏形态及滞回曲线、骨架曲线、承载力、延性、刚度、耗能能力等性能指标。结果表明:剪跨比为2.5的试件在低周反复荷载作用下发生弯曲破坏,配钢率对试件破坏形态的影响较小,但配钢率增大能够抑制混凝土裂缝的开展,延缓试件的破坏;试件的滞回曲线饱满、对称,延性好,耗能能力强,刚度退化先快后慢;随着配钢率增大,试件的滞回环面积越来越大,承载力显著提高,延性明显改善,刚度退化变缓,但耗能能力变化较小。

INFLUENCE OF STEEL RATIO ON SEISMIC PERFORMANCE OF STEEL REINFORCED CONCRETE SPECIAL-SHAPED COLUMN

Sixteen steel reinforced concrete special-shaped column specimens were designed, including four L-shaped columns, four T-shaped columns loaded along the web, four T-shaped columns loaded along the flange, and four cross-shaped columns. The influence of steel ratio on seismic performance of a steel reinforced concrete special-shaped column was analyzed by using tests and finite element analysis. The failure patterns and seismic behaviors, such as hysteretic loops, skeleton curves, strength, ductility, stiffness and energy dissipation capacity, were obtained. The research results show that the failure pattern of all tested specimens with a shear span ratio of 2.5 was flexural failure. The influence of steel ratio on the failure pattern of specimens is not obvious, but as the steel ratio increasing, the cracking of the concrete can be inhibited and the damage of the specimens can be delayed. The hysteretic loops were symmetric and plump. The ductility and energy dissipation capacity were good, and the stiffness degenerated from fast to slowly. With the increase of steel ratio, the area of hysteretic loops becomes larger and larger, the bearing capacity and ductility are significantly improved, and the speed of stiffness degradation slows down. But the steel ratio has no significant influence on the energy dissipation capacity of specimens.