圆CFRP-钢管混凝土压弯构件静力性能试验研究

进行了32个圆CFRP-钢管混凝土压弯构件的试验研究。结果显示,构件的载荷-中截面挠度曲线可以分为弹性阶段、弹塑性阶段和下降阶段,构件的破坏属于延性破坏。分析表明,从加载之初直到极限荷载,钢管和CFRP在纵向和环向都可以协同工作,环向应变沿截面周边分布不均匀;钢管纵向应变沿截面高度的分布基本符合平截面假定;纵向受压的钢管存在内力重分布过程,纵向受拉区钢管对核心混凝土的环向约束效果不显著;构件的挠曲线大致为正弦半波曲线。采用纤维模型法分析圆CFRP-钢管混凝土压弯构件的荷载-中截面挠度曲线,分析结果与试验结果吻合较好且偏于安全。

Experimental study on static performance of the eccentrically compressed concrete filled circular CFRP-steel tubular members

In total 32 eccentrically compressed concrete-filled circular CFRP-steel tubular members were experimentally investigated. Results have shown that load-middle cross-section deflection curves can be defined as elasticity stage, elasto-plasticity stage and softening stage; the failure mode of the members belong to ductility failure. Analysis has shown that, steel tube and CFRP can cooperate longitudinally and circumferentially both from zero load till the ultimate load, and circumferential strains around the cross-section are not even. Distribution of longitudinal strains of the steel tube over depth of the cross-section obeys the plane section assumption with the load from zero till the ultimate. There exists process of inner force redistribution in the area where steel tube compressed longitudinally; the steel tube longitudinally tensioned has little circumferential confinement effect on core concrete. Deflection curves of the members can be regarded as half sin wave approximately. The fiber element approach was used to analyze load-middle cross-section deflection curves of the eccentrically compressed concrete-filled circular CFRP-steel tubular members, and the predicted results agree well with those of test and are on the safe side.