STABILITY LIMIT AXIAL FORCE AND ALLOWABLE ROTATION ANGLE OF STEELCONCRETE COMPOSITE COLUMNS

在日本，钢筋混凝土组合柱已被用作高层建筑的梁柱构件。高层建筑低层柱在地震作用下承受高轴向压缩力和反复弯曲。结果表明，竖向力对钢筋混凝土的非弹性性能影响很大，对此，AIJ《钢筋混凝土标准》规定了要求变形能力的梁柱轴向荷载的极限值。目的是研究钢-混凝土组合柱在恒定压缩载荷和反复弯曲作用下的强度和性能。试验主要参数选择柱轴向载荷比。对36根方形钢管混凝土柱和40根圆形钢管混凝土柱进行了试验。试样的钢部分为冷弯方形和圆形截面。除轴向载荷比外，还选择了宽厚比和径厚比作为实验参数。测试了22根SRC柱。除轴向载荷比外，还选择钢面积比作为试验参数。从试验结果出发，讨论了其非弹性性能、最大强度、耗能能力和变形能力。给出了轴向载荷比与柱临界转角之间的关系。

Sreel-concrete composite columns have been used as the beam-column members of high-rise building in Japan. The columns of lower stories of high rise building are subjected to both high axial compressive force and repeated bending under the earthquake excitation. It is indicated that the effect of vertical force on the inelastic behavior is very large, and for this Steel Reinforced Concrete Standard of AIJ prescribes a limiting value of axial load for a beam-column which requires the deformation capacity.The objectives is to study the strength and behavior of steel-concrete composite columns subjected to constant compressive load and repeated bending. As the main test parameter, axial load ratio on a column was selected.Thirty-six concrete filled steel square and forty concrete filled steel circular tubular columns are tested. The steel portion of a specimen is a cold-formed square and circular section. In addition to the axial load ratio, width-thickness ratio and diameter-thickness ratio are selected as the experimental parameters.Twenty-two SRC columns are tested. In addition to the axial load ratio, steel area ratio is selected as the experimental parameters.From the test results, inelastic behavior, maximum strength, energy dissipation capacity and deformation capacity are discussed. We have shown relations between axial load ratio and critical rotation angle of a column.