钢骨截面延展性对高含钢率SRC柱滞回性能的影响研究

Effect of shape distribution of encased steel section on hysteretic performance of steel reinforced concrete columns with high steel ratio

在"钢骨截面延展性对高含钢率SRC柱静力性能的影响研究"的基础之上,该文通过一组含钢率为15%的SRC压弯构件反复加载试验,结合理论分析和有限元数值计算,研究了钢骨截面延展性对高含钢率SRC柱骨架曲线、滞回曲线、耗能能力和延性等抗震性能指标的影响,并分析了钢骨、钢筋和混凝土相互作用的机理。研究表明:1构件承载能力和耗能能力随钢骨截面延展性系数D提高而线性增加;2承载能力、耗能能力、延性和卸载刚度均随钢骨截面模量因子α的增大而显著增大;承载能力随约束混凝土因子β线性增加,但β对滞回曲线和变形能力的影响很小;3在加载后期,钢骨翼缘的局部屈曲和混凝土压溃退出工作是导致承载力下降的主要原因;构件的后期承载力、延性和耗能主要依赖于钢骨的贡献。

A series of steel reinforced concrete（ SRC） columns,with high steel ratio of 15% and different shape distribution coefficient D values,were tested under cyclic loading. Based on the experimental results and finite element analysis results,the influences of shape distribution of encased steel section on those seismic performance indices,such as skeleton curve,hysteretic curves,energy dissipation capacity and ductility of SRC columns with high steel ratio,were studied,and the interaction mechanism among the encased steel,steel bars and concrete was analyzed. The results indicate that SRC columns with high steel ratio possess outstanding seismic behaviors; the bearing capacity and energy dissipation capacity may increase with increasing the factor of section modulus α and D values; the factor of confined concrete β may significantly affect the bearing capacity,but it has little effect on the hysteresis loops and ductility. The decline of bearing capacity of SRC columns may primarily attribute to the buckling failure of steel plates and the crushing failure of concrete. The bearing capacity,ductility and energy dissipation in the later period of structural members mainly rely on the contributions of encased steel.