中文摘要：

圆中空夹层钢管混凝土是在两个同心放置的圆钢管中间灌注混凝土而形成的一种新型组合结构。已有学者对其在轴压、压弯、纯弯等方面及在往复荷载下的力学性能进行研究,当被用作构筑物独立柱、输电塔杆、发电风车支架时其抗扭性能是十分重要的,但目前还未见对这方面研究的报道。利用有限元软件ABAQUS建模对钢管混凝土纯扭构件进行计算,数值模拟结果的正确性得到了试验结果的验证。在此基础上,对圆中空夹层钢管混凝土纯扭构件的扭矩-转角全过程曲线进行了计算。计算结果表明,扭矩-转角曲线可分为三个阶段：弹性段、弹塑性段和塑性强化段,通过对这三个阶段中内外钢管和混凝土的应力分布云图及其相互作用的分析,揭示了圆中空夹层钢管混凝土在扭矩作用下的工作机理。

英文摘要：

Concrete filled double-skin steel tubular（CFDST） column is a new type of composite structure filled with concrete between two concentric steel tubes.The outer steel tube and the inner steel tube are circular hollow section（CHS）.Some scholars have studied the mechanical properties of the（CFDST） column subjected to axial compression,compression bending,pure bending,hysteresis load etc.It is very important for the torsion property of the（CFDST） column when used as an independent column,transmission tower,and windmill power generation.But there is no report on torsion performance of the（CFDST） column now.The pure torsion property of the concrete filled steel tube column is analyzed by ABAQUS software,and it is verified by the experimental results.The torque-angle relationship curve of the（CFDST） subjected to pure torsion is calculated afterwards.The results indicate that the torque-angle curve can be divided into elastic,plastic and plastic hardening stages.Based on the result,the stress distribution of steel tubes and concrete and the interaction between the steel tubes and concrete are analyzed.Finally,the work mechanism of the（CFDST） column under torsion is revealed.