SRC-RC 竖向混合结构转换柱刚度退化全过程分析

为了研究SRC-RC竖向混合结构中转换柱的刚度退化规律，设计并完成了17根试件的抗震性能试验，包括16根转换柱试件和1根钢筋混凝土柱对比试件。试验得到了转换柱的特征点刚度。转换柱的弹性刚度高于钢筋混凝土柱；试件的刚度随型钢延伸高度的增大呈现先降后升的变化规律；增大轴压比可以提升试件的刚度；型钢的配钢率对侧移刚度的影响相对较小。转换柱刚度退化的全过程可分为3个阶段，呈现出先快后慢的规律。刚度退化在混凝土开裂至试件屈服阶段较为迅速，屈服后则相对平缓。转换柱试件与钢筋混凝土柱对比试件具有相似的刚度退化规律。以16根转换柱试件为基础，对刚度退化曲线进行了拟合并给出了公式，可为混合结构的设计提供参考。

Analysis of stiffness degradation process of transfer column in SRC-RC hybrid structure

Experiment of 17 specimens was carried out including 16 transfer columns and 1 reinforced concrete column under cyclic shear. The stiffness degeneration rule of transfer columns was researched. Stiffness of characteristic points was deduced from the test. Increment of axial compressive ratio can promote the stiffness. Displacement ductility changes with the increase of the extension length of shape steel, increasing at first and then decreasing. Area ratio of shape steel has little effect on the stiffness. Stiffness degradation process of transfer column was analyzed and divided into three parts. Although the configuration and steel arrangement has effect on stiffness, the 16 transfer columns show similar process of stiffness degradation. Stiffness of transfer column degenerated quickly at the period from cracking to yielding, but slowed down after yielding, same as that of the reinforced concrete column. Based on the test of 16 transfer columns, formulae were put forward to calculate the stiffness degradation, which can provide reference for hybrid structure design.