CFRP约束圆中空夹层钢管混凝土短柱轴心受压性能试验研究

Experimental research on axial compression performance of CFRP-confined concrete-filled double skin steel tube stub columns

对圆中空夹层钢管混凝土(CFDST)短柱和CFRP约束CFDST(CFRP-CFDST)短柱进行了轴压试验,研究混凝土强度和CFRP粘贴层数对CFRP约束CFDST短柱轴压性能的影响,得到了CFDST短柱和CFRP约束CFDST短柱的典型破坏模式、荷载—位移曲线及荷载—应变曲线。试验结果表明:与CFDST试件相比,CFRP约束CFDST试件的极限承载能力显著提高,且贴布层数越多,钢管混凝土短柱的极限承载力越高。给出了避免内钢管先于外钢管屈曲破坏的内钢管最小壁厚计算式,并提出了CFRP约束CFDST短柱的轴压极限承载力计算式,该计算式计算结果与试验结果吻合较好。

In this work,the axial compression tests of circular concrete-filled double skin steel tube(CFDST)stub columns and CFRP-confined CFDST(CFRP-CFDST)stub columns were carried out.The influences of concrete strength,the number of CFRP layers on the axial compression performance of CFRP-confined CFDST stub columns were investigated.The typical failure modes,the load-displacement curves and loadstrain curves of CFDST stub columns and CFRP-confined CFDST stub columns were obtained.The test results show that the ultimate bearing capacity of CFRP-confined CFDST specimens is significantly improved compared with that of CFDST specimens.And the more layers of CFRP,the higher the ultimate bearing capacity of CFST stub columns.Finally,the calculation formula of the minimum wall thickness of the inner steel tube to avoid the buckling failure of the inner steel tube prior to that of the outer steel tube is given.And a calculation formula of the ultimate bearing capacity of CFRP-confined CFDST stub columns under axial compression is proposed.The prediction results of the presented calculation method agree well with the experimental results.