圆CFRP-钢管混凝土偏压构件的静力性能研究

Static Performances Analysis on Eccentrically Compressed Concrete Filled CIrcular Cfrp-Steel Tubular Columns

目的了解圆CFRP-钢管混凝土偏压构件的静力性能,为理论计算提供依据.方法以12根圆CFRP-钢管混凝土偏压构件的静力试验为基础,对其展开理论分析.结果发现从加载之初直到最大承载力,钢管和CFRP筒在纵向和环向都可以协同工作,环向应变沿构件截面周边分布不均匀;纵向受压最大点的钢管存在内力重分布过程:在加载初始阶段,钢管以承受纵向压力为主,进入屈服阶段后,钢管以承受环向拉力为主;纵向受拉最大点的钢管对核心混凝土没有套箍作用.结论从加载之初直到最大承载力,沿截面高度的钢管纵向应变分布符合平截面假定;在其他参数相同的情况下,侧向挠度随着偏心距或构件长度的增大而增大;在其他条件相同的情况下,同一载荷下的纵向应变随着偏心距或试件长度的增大而增大,但达到屈服载荷时的纵向应变值却十分接近.

To understand static performances of eccentrically compressed concrete filled circular CFRP-steel tubular columns and to provide theory basis for calculation, 12 eccentrically compressed concrete filled circular CFRP-steel tubular columns are tested and their results are analyzed. It was found that steel tube and CFRP tube could cooperate longitudinally and circumferentially from zero load till maximum load and circumferential strains around the section are not even. There exists inner force redistribution at the point where longitudinal compress strain is the biggest： the steel tube bears longitudinal pressure mainly at first and bears circumferential tension mainly after yielding. The steel tube whose longitudinal tension strain is the biggest has no confinement effect on core concrete. The steel tube longitudinal strain distribution over the section depth obey the plane section assumption approximately from zero load till maximum load. Under the condition that other factors are the same, lateral deflection increases as eccentricity or member height increases. Under the condition that other factors are the same, Steel tube longitudinal strain increases as eccentricity or member height increases, but the strain value is approximately the same when members yielding.