圆钢管混凝土压弯剪构件受力性能分析

Research of circular concrete-filled steel tubular members subjected to shearing and axial compression

本文基于有限元软件ABAQUS对圆钢管混凝土压弯剪构件力学性能进行研究,通过对以往试验结果的模拟对比验证了模型的合理性,并对典型构件受力全过程荷载-位移曲线、构件破坏形态、荷载分配、应力分布和界限剪跨比进行了研究。研究结果表明:典型构件的荷载-位移曲线大致分为弹性阶段、弹塑性阶段和塑性阶段;根据剪跨比的不同可将构件的破坏形式分为压剪、压弯剪和压弯;轴压比的改变对荷载分配曲线的形状有较大影响;剪跨比、轴压比、含钢率、钢材强度及混凝土强度对构件抗剪承载力和弹性阶段刚度都有不同程度的影响。

Concrete-filled steel tubular（ CFST） have many advantages,and they are used extensively in roadbridge project and high-rise buildings. During the period of service,the composite members may be subjected to shearing and axial compression. The study of behavior of circular CFST members subjected to shearing and axial compression is carried out using ABAQUS,and finite element model（ FEM） is compared with experimental results to verify the reliability of model. The load-displacement curve,failure modes,load-distribution,stress distribution and boundary shear-span-ratio are investigated respectively. The influential parameters such as shear-span-ratio,axial-compression-ratio,ratio of steel tube,strength of steel and concrete are investigated to shearing capacity of circular CFST members. The result indicates that load-displacement curve of circular CFST members is divided into elastic stage,elastic-plastic stage and plastic stage. According to different shear-span-ratios,the failure modes of members are divided into compression-shearing, compression-bending-shearing and compression-bending. The axial-compression-ratio has a great effect on the shape of load-distribution curve. Finally,the shear-span-ratio,axial-compression-ratio,ratio of steel tube,strength of steel and concrete have some effect on shearing capacity of circular CFST members and the elastic stiffness.