Method of Evaluating Performance of RC and SRC Beam-Columns Subjected to Repeated Horizontal Force

钢筋混凝土梁柱和钢与钢筋混凝土组合梁柱在地震力作用下经常发生破坏，出现强度劣化、变形累积等累积损伤。累积损伤的大小取决于施加在梁柱上的轴力，累积损伤过程中存在收敛-发散行为，本文提出了梁柱在水平反复荷载作用下的特征曲线以及利用该曲线评价梁柱性能的方法。接下来，进行了钢筋混凝土和型钢混凝土梁柱的试验，以验证曲线的有效性。特征曲线称为临界轴力-轴向位移曲线。进行了6个受弯破坏类型和剪切破坏类型的RC试件和2个受弯破坏类型的SRC试件的试验。试验由两部分组成：获得临界轴力-轴向位移曲线的试验和验证该曲线有效性的试验。临界轴力-轴向位移曲线表达了临界轴力与最大轴向位移之间的关系，在该关系下，轴向位移的累积收敛。还进行了与试验相对应的分析，发现分析结果与试验结果吻合很好。得到的结果如下：临界轴力-轴向位移曲线呈滞后形式。累积损伤的进程在曲线内侧收敛，但在外侧发散。梁柱的累积损伤随着轴力的大小和临界轴力-轴向位移曲线的下降斜率的增大而增大。

Reinforced concrete beam-columns and composite steel and reinforced concrete beam-columns subjected to a seismic force often fail and the cumulative damage such as the strength deterioration and the accumulation of deformation occur. Magnitude of the cumulative damage depend on the axial force applied on the beam-column and the convergence-divergence behavior exists in the progress of cumulative damage.In this study, the characteristic curve of beam-columns under a repeated horizontal force and the method of evaluating the performance of beam-columns by using the curve is proposed. Next, RC and SRC beam-columns were tested to verify the validity of the curve. The characteristic curve is named as critical axial force-axial displacement curve.Six bending failure type and shear failure type RC specimens and two bending failure type SRC specimens were tested. Experiments compose of two parts ; tests for obtaining the critical axial force-axial displacement curve and that for proving the validity of the curve. The critical axial force-axial displacement curve expresses the relation between the critical axial force and the maximum axial displacement under which the accumulation of axial displacement converges. Analyzes in correspondence to tests were also carried out and it was found that analytical results agree with test ones very well. Obtained results are as follows ;Critical axial force-axial displacement curve takes a form of hysteresis. The progress of cumulative damage converges at the inside of the curve, but diverges at the outside. The cumulative damage of beam-column increases with the increase of the magnitude of axial force and the descending slope of the critical axial force-axial displacement curve.