【摘要】 以横向CFRP约束系数、纵向CFRP增强系数和混凝土立方体抗压强度为主要参数,进行了18个CFRP-方形截面钢管混凝土(S-CF-CFRP-ST)构件扭转性能试验研究。试验结果表明,S-CF-CFRP-ST构件的扭矩-转角曲线对应试件受力的弹性阶段、弹塑性阶段和塑性阶段;钢管和CFRP可以协同工作;纵向应变与横向应变均为拉应变,45°方向为压应变;构件的变形近似符合平截面假定。应用ABAQUS有限元分析软件模拟了S-CF-CFRP-ST构件的扭矩-转角曲线,计算结果与试验结果吻合良好。有限元参数分析结果表明,钢材屈服强度、混凝土强度、CFRP层数和含钢率的提高不改变S-CF-CFRP-ST构件的扭矩-转角曲线的形状;但钢材屈服强度或含钢率的提高可以显著提高受扭承载力,混凝土强度的提高对构件承载力有所提高,而CFRP层数的增加可使承载力略有提高;含钢率的提高可以提高构件弹性阶段的刚度。更多还原

【Abstract】 Taking the confinement factor of the transverse CFRP,strengthening factor of the longitudinal CFRP and the cubic compressive strength of concrete as the principal factors,the torsional behavior of 18 square concrete filled CFRP-steel tube( S-CF-CFRP-ST) were experimentally investigated. The test results show that the torque-rotation angle curves of the composite members can be divided into elastic stage,elasto-plastic stage and plastic stage. Analysis on the experimental results shows that the steel tube and the CFRP tube can cooperate,and the longitudinal and the transverse strains are all tensile while the strain in 45° direction is compressive. It is also found that the deformation of the specimen satisfies the plane section assumption approximately. The torque-rotation angle curves are simulated by using ABAQUS software and the predicted results agree well with the experimental ones. Parametric analysis shows that,the increases of the yield strength of the steel tube,the compressive strength of the concrete,the layers of the CFRPs and the steel ratio do not change the shape of the torque-rotation curve of the S-CF-CFRP-ST,while these increases will enhance the torsional load carrying capacity of the S-CF-CFRP-ST to different degrees,and the increase of the steel ratio can enhance the elastic stiffness of the S-CF-CFRP-ST.更多还原