FRP管-混凝土-钢管组合短柱轴压性能试验及有限元分析

为了研究FRP管-混凝土-钢管组合短柱的轴压性能,进行了3个实心组合短柱的轴压试验.基于非线性有限元分析软件ANSYS,通过选择合适的单元类型以及材料的本构关系,对实心组合短柱进行了数值仿真分析,并与试验结果进行对比,证明了所采用的非线性有限元分析模型可以较好地模拟实心组合短柱的受力过程.结合已建立的有限元模型,开展了参数的敏感性分析,探讨了FRP管厚度、钢管厚度和强度、核心混凝土强度等参数对实心组合短柱轴压性能的影响.模拟结果表明:FRP管厚度对实心组合短柱的轴压性能有显著影响,钢管厚度和强度对实心组合短柱的影响规律较相似,对第二线性阶段斜率均无影响,其中钢管厚度对实心组合短柱的初始刚度略有影响,核心混凝土强度变化对极限承载力有较大影响.

Experiment and finite element analyses for axial compression behavior of FRP-concrete-steel short composite columns

In order to study the axial compression behavior of FRP-concrete-steel short composite columns, the axial compression experiments on 3 short solid composite columns are conducted. By using nonlinear finite element analysis software ANSYS, the numerical simulation is carried out on short solid composite columns under proper selection of unit types and the constitutive relations of materials. The comparison between the simulation results and the tests results verifies that the proposed nonlinear finite element analysis model can simulate the stress procedure of the short solid composite columns. On the basis of the established finite element models, sensitivity of parameters is analyzed to discuss the influences of the thickness of FRP tube, the strength and thickness of steel tube and the strength of core concrete on axial compression behavior of short solid composite columns. The simulation results show that the thickness of FRP tube has significant impact on the axial compression behavior of short solid composite columns. The strength and thickness of steel tube show similar influence rule, they both have no effect on the slope of the second linear phase. The initial stiffness of short solid composite column is slightly affected by the thickness of steel tube. The change of the strength of core concrete has great influence on the ultimate capacity.