Concrete filled double skin circular tubular members subjected to pure bending and centric compressive loading

摘要

A Concrete Filled Double Skin CircularTubular (CFDST) member consists of double concentricrnsteel tubes and in-filled concrete between the two tubes. The CFDST member with a hollow section is consequentlyrnlighter than an ordinary concrete filled steel tubular, so-called CFT member. Twelve specimens of eachrnpure bending test and centric loading test have been prepared.Two of testing parameters are diameter-to-thicknessrnratio and inner-to-outer diameter ratio, ranging from 70 to 160 and from 0 to 0.70, respectively. As the results,rnboth bending and centric loading strengths of CFDST can be estimated based on a CFT’s design formula. Bothrnstrengths were also affected by inner-to-outer diameter ratio, D_i/D_o. Discussions being focused on elasto-plasticrnstress under plane stress condition are given. A comparison of confined stress intensity being induced by therndouble tubes of two tests is also discussed.