钢筋屈曲状态判断方法研究

Bucking of longitudinal bars in concrete columns under earthquake may lead to seismic behavior deterioration and bearing capacity degradation, or even invalidation and structural collapse. In the existing material tests of steel bar and experimental studies of reinforcing concrete component, it's common to define the beginning of bending under compression as the onset of buckling through visual observation, which is inaccurate. Three determining methods are proposed to predict the onset of buckling based on experimental results of cyclic tension-compression tests of steel bars and analysis of the strain difference of opposite faces, lateral deflection and their variation respectively. The analytical results of 23 cyclic loading tests of steel bars using these methods indicate that the combination of "critical lateral deflection"method and "critical variation of lateral deflection" method can predict the onset of buckling more reasonably and accurately.