以名义含钢率、外钢管强度和空心率为主要变化参数,设计了6根圆中空夹层钢管混凝土和1根双层空钢管试件,对其进行了扭转试验研究。试验结果表明:在加载过程中,钢管和混凝土变形协调,共同工作;试件表现出很好的塑性性能;试件名义含钢率和外钢管强度越大,试件抗扭承载力也越大;空心率越大,试件抗扭承载力也越大;圆中空夹层钢管混凝土比双层空钢管抗扭承载力有明显的提高。同时用有限元方法对试件扭矩-转角全过程曲线进行计算,计算结果与试验结果吻合良好。
Six concrete-filled double-skin circular steel tubes and one double-skin hollow circular steel tube were designed and tested under pure torsion load. The primary parameters in the experiment are the nominal steel ratio, the steel strength of outside tube and the hollow ratio. Experimental results show that steel tubes work together with concrete and they are deformed harmoniously in loading process. All specimens present good plasticity. The greater nominal steel ratio and steel strength are, the greater torsional capacity is. The higher the hollow ratio is, the greater the torsional capacity is. The torsion capacity of concrete-filled double-skin circular steel tube is significantly improved comparing with double-skin hollow steel tube. Torque-angle relation curve of concrete-filled doubleskin steel tube subjected to pure torsion was analyzed by using finite element software ABAQUS. Calculation results are in a good agreement with experimental results.