圆套圆中空夹层钢管混凝土压扭性能研究

Research on compression and torsion performance of circular-in-circual concrete filled double-skin steel tubular

为研究圆套圆中空夹层钢管混凝土的压扭性能,完成了12个该类构件在先压后扭受力下的静力性能试验,变化参数为空心率、含钢率和轴压比等。结果表明:构件的抗扭承载能力较好,在发生较大的扭转变形后,可以保持较高的承载力。钢管中截面三个测点的应变变化情况基本一致,弹性阶段外钢管测点的剪应变与构件扭转角呈线性关系。在一定的轴压比范围内(n≤0.3),构件的抗扭承载力随轴压比的增大稍有提高,构件的刚度也得到了一定程度的增强。利用ABAQUS有限元分析软件对构件的扭矩-转角曲线进行了模拟,模拟结果与试验结果吻合较好。参数化分析表明:外钢管变形较为严重,承担大部分的截面扭矩,内钢管变形较小。外钢管与混凝土接触面的法向应力和剪应力较大。混凝土强度等级对构件的抗扭承载力影响很小。随着钢材的强度等级以及含钢率的提高,构件的抗扭承载能力提高很大。

In order to study the compression and torsion performance of circular-in-circual concrete filled double-skin steel tubular,the static performance test of 12 specimens of this type under the first compression and then the torsion force was completed,and the parameters such as hollow rate,steel content and axial compression ratio were changed.The results show that the torsional bearing capacity of the specimen is better,and it can maintain a higher bearing capacity after a large torsional deformation.The strain changes of the three measuring points in the section of the steel pipe are basically the same,and the shear strain at the measuring point of the outer steel pipe during the elastic stage is linearly related to the torsion angle of the component.Within a certain range of axial compression ratio(n≤0.3),the torsional bearing capacity of the specimen can be slightly increases with the increase of axial compression ratio,and the stiffness of the specimen is enhanced to a certain extent.ABAQUS was used to simulate the torque-rotation curve of the test piece,the simulation results are in good agreement with the test results.The parametric analysis shows that the outer steel pipe deforms more seriously,bears most of the cross-sectional torque,and the inner steel pipe deforms less.The contact stress and shear stress between the outer steel pipe and the concrete are relatively large.The strength level of concrete has little effect on the torsional bearing capacity of the component.The increase in the strength grade and steel content of the steel will greatly improve the torsional bearing capacity of the component.