内配钢筋钢管混凝土构件轴心受拉性能研究

EXPERIMENTAL RESEARCH ON CONCRETE-FILLED STEEL TUBES WITH REINFORCING BARS UNDER AXIAL TENSION

为研究内配钢筋钢管混凝土构件的轴拉性能,通过对9个试件进行轴拉试验,获得了试件的荷载-位移曲线,荷载-应变曲线和轴拉极限承载力等试验数据。结果表明:钢管混凝土构件在受拉荷载作用下,由于内部混凝土对外钢管环向收缩的约束作用,使其极限承载力相比空钢管提高约10%,内配钢筋在构件达到轴拉极限承载力时屈服。在试验基础上提出了用于分析轴心受拉构件的有限元模型,模型的计算结果与试验结果吻合较好。通过对比国内外相关设计规范规定的内配钢筋钢管混凝土构件的轴拉极限承载力的计算式,提出了该类型构件的轴拉承载力计算式,并将公式计算值与试验值进行了对比。对比结果表明:提出的轴拉承载力计算式与试验结果吻合较好。

In order to investigate the mechanical properties of concrete-filled steel tubes with reinforcing bars under axial tension,9 specimens were tested under axial tension. The load-displacement curve,load-strain curve and ultimate bearing capacity of specimens were obtained. The tested results showed that the ultimate bearing capacity of concrete-filled steel tubes increased by about 10% due to the restraint effect on the outer tube of internal concrete under tension. The reinforcing bars inside the concrete could reach the yielding stage when the specimen reached its ultimate strength under axial tension. A finite element model was established on the basis of experiment and verified against test results,and results showed that the finite element model could fit the experiment results well. The suitability of current design methods for the ultimate tensile strength of this kind of specimens were evaluated by comparing with the test results,the design equation was proposed and showed good agreement with test results.