CFRP-钢管-CFRP复合钢管约束海砂混凝土短柱轴压试验

Research on axial compression mechanical behavior of sea sand concrete filled CFRP-steel-CFRP composite steel tubular stub column

以钢管壁厚、钢管屈服强度、碳纤维增强聚合物(carbon fiber reinforced polymer,CFRP)层数和位置、混凝土强度等为研究参数,进行19根CFRP-钢管-CFRP复合钢管约束海砂混凝土短柱的轴压试验,分析试件破坏模式、荷载-应变曲线、结构承载力等,并讨论现有算法对承载力计算的适用性.研究结果表明:内外壁CFRP与钢管的组合对核心混凝土有良好的复合约束作用,可大幅提高结构承载力;钢管内外壁张贴CFRP后,其结构破坏模式由剪切破坏变为腰鼓破坏;钢管最先开始屈服,CFRP层数决定纤维布的断裂宽度和分布;荷载-应变曲线在强化阶段呈明显线性上升特性,二次刚度由CFRP层数决定;与外壁张贴CFRP试件相比,内壁张贴CFRP试件的结构承载力更大.

19 sea sand concrete-filled CFRP-steel-CFRP composite steel tubular stub columns under axial loads are tested by taking the steel tube wall thickness,yield strength,CFRP layers and loca­tion,and concrete strength as research parameters.The failure modes of specimen,load-strain rela­tions and bearing capacity are analyzed.The applicability of existing algorithms to bearing capacity is also discussed.The results show that the combination of CFRP and steel tube performs a good restraint effect to core concrete and can greatly improve the structural bearing capacity.The failure mode of the structure is changed from shear failure to waist drum failure when CFRP layers are bonded on the inner and outer walls of the steel tube.The steel tube is the first to yield and the number of the CFRP layers determines the fracture width and distribution of the fiber cloth.The load-strain curve shows an obvious linear rise during the strengthening stage.The secondary stiffness is determined by the number of the CFRP layers.The structural bearing capacity of CFRP bonding on inner wall is larger than that of CFRP bonding on outer wall.