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

钢-混凝土组合柱作为高层建筑的梁柱构件在日本已得到广泛应用。高层建筑低层柱在地震作用下既承受较高的轴压，又承受反复弯曲。研究表明，竖向力对组合柱的弹塑性性能影响很大，AIJ《型钢混凝土规范》规定了对变形能力有要求的梁柱轴压限值，目的是研究型钢混凝土组合柱在恒压反复弯曲作用下的强度和性能。以轴压比为主要试验参数，对36根方钢管混凝土柱和40根圆钢管混凝土柱进行了试验研究。试样的钢部分是冷成型的方形和圆形截面。除了轴压比外，还选取了宽厚比和径厚比作为试验参数，进行了22根型钢混凝土柱的试验。试验中除轴压比外，还选取配筋率作为试验参数，对试件的弹塑性性能、最大承载力、耗能能力和变形能力进行了分析。本文给出了轴压比与柱的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.