管中管混凝土柱轴压情况下受力性能研究

Study on Mechanical Property of Reinforced Concrete Filled Double Steel Tubular Columns subjected to Axial Compression

同心配置双管形成管中管混凝土可以改善大径管带来的问题。共设计了7根管中管混凝土短柱试件,以内管配钢率和屈服强度为主要变化参数,对其进行轴压试验研究,分析了试件的破坏特征、承载力和荷载-位移曲线,给出了变形和承载力的试验结果,研究了各影响参数对试件变形和承载力的影响。试验结果表明:较普通钢管混凝土柱,内配钢管的钢管混凝土柱改变了其破坏形态,提高了其承载能力,改善了试件的延性;内外钢管在试件达到承载力时都已经屈服,充分发挥了钢材的作用;采用有限元软件ABAQUS进行了数值计算分析,并将计算结果与试验结果进行了比较,吻合良好。

The problems caused by huge diameter in concrete-filled steel tube can be improved using concentric configuration of double tube. With two main changes on internal steel ratio and yield strength, seven short reinforced concrete filled double steel tubular columns were designed, and axial compression experiments were conducted. The failure mode, ultimate bearing capacity and load-displacement curve of each specimen were studied,and the influencing factors to the above parameters were evaluated. The result indicates that reinforced concrete filled double steel tubular columns have different failure mode, stronger bearing capacity and better ductility, as compared to common concrete filled steel tubular column. Internal and external steel tubes have yielded before the columns reach bearing capacity, and this fully utilizes of the capacity of steel. In addition, a finite element analysis utilizing ABAQUS is presented, and the results are in a good agreement with test results.