圆CFRP-钢管混凝土压弯构件滞回性能的参数分析与恢复力模型

PARAMEYRIC ANALYSIS AND RESTORING FORCE MODEL OF HYSTERETIC BEHAVIOR OF CIRCULAR CONCRETE FILLED CFRP-STEEL TUBULAR BEAM-COLUMN

应用有限元软件ABAQUS模拟了圆CFRP-钢管混凝土压弯构件的中截面侧向荷载-挠度滞回曲线和变形模态,模拟结果与试验结果的比较表明该模型是合理的。研究了受力全过程中钢管与混凝土之间的相互作用力,发现始终是在受压区的相互作用力较大,并且钢管屈服后该力显著增大。分析了CFRP的层数、轴压比和长细比等参数对滞回曲线的影响,发现轴压比的影响效果最显著:试件的侧向承载力和刚度都减小,并且在加载后期曲线出现了下降段。最后提出了圆CFRP-钢管混凝土压弯构件的恢复力模型,依据该模型的计算结果与有限元模拟的结果吻合良好。

The lateral load-deflection hysteretic curves at the mid-height and deformation mode of the circular concrete filled CFRP-steel tubular beam-column are simulated by using the finite element software ABAQUS. Comparison between the simulated results and the experimental results shows that the numerical model is reasonable. The interactional forces between the steel tube and the concrete during the full loading process are studied. It is found that the interactional force in the compressive region is larger than that in the tensile region throughout the process, and this force increases dramatically after the steel tube yields. The influences of some parameters, such as layers of the CFRPs, the axial compressive ratio and the slenderness, on the hysteretic curves are analyzed, which shows that the axial compressive ratio has the most obvious effect, as both the lateral load carrying capacity and the stiffness of the beam-column reduces, and a softening stage occurs in the hysteretic curve at the end of the loading process. Finally, the restoring force model of the circular concrete filled CFRP-steel tubular beam-column is proposed, and the calculated results based on this model agree well with those of the finite element simulation.