【作者】 张鹏鹏；

【导师】 王文达；

【作者基本信息】 兰州理工大学 ， 结构工程， 2010， 硕士

【摘要】 随着钢管混凝土结构在工程中应用的日益增多,尤其是近年来火灾频发,使深入研究钢管混凝土结构火灾后的力学性能变得越来越重要。本文主要对火灾后钢管混凝土组合框架的力学性能进行了研究,具体进行了以下几方面的工作：(1)选择合适的热工参数模型,运用ABAQUS建立钢管混凝土柱-钢梁框架温度场有限元分析模型,建立模型模拟现有试验,并将模拟结果与试验数据对比验证模型的有效性。同时建立钢管混凝土柱-钢梁框架的受火模型,简要分析了框架在不同时刻的温度场分布。(2)选取合理的材料本构关系、单元模型和求解方法,考虑钢管与混凝土之间的约束效应以及接触面模型,建立火灾后钢管混凝土柱-钢梁框架力学性能有限元分析模型,并模拟现有试验以验证模型的有效性。利用前述模型,建立火灾后钢管混凝土柱-钢梁框架力学性能分析模型,并简要对比分析火灾后与常温下钢管混凝土柱-钢梁框架力学性能区别。(3)利用上述有限元模型,建立火灾后钢管混凝土柱-钢梁混凝土楼板组合框架典型算例,并对可能影响火灾后组合框架荷载-位移关系的主要因素,如：钢管钢材强度、核心混凝土强度、柱截面含钢率、柱的长细比、柱轴压比、防火保护层厚度、梁柱线刚度比、梁柱强度比等参数进行分析,得到了各参数对火灾后钢管混凝土组合框架荷载-位移曲线的影响规律。并在此基础上提出了火灾后钢管混凝土组合框架荷载-位移骨架曲线的简化模型。更多还原

【Abstract】 With the increasing use of concrete-filled steel tubular (CFST) structure in engineering, especially fire disaster happens frequently in recent years, it is severely significant to further the research on the mechanical behavior of CFST structure after exposure to fire.The paper describes the research studies on the mechanical behaviors of CFST composite frame after exposure to fire. The main achievements can be summarized as follows:(1) Accurate thermal model was assumed, and CFST column to steel beam composite temperature field FEM model was also developed. The results obtained from the FEM model were verified against those experimental results. Meanwhile, the temperature distribution was analysised with the CFST composite model under fire.(2) Reasonable material model, element type and solution method were assumed. The mechanical behavior model of CFST columns to steel beam composite frame was developed considering the restrained effect and interface model of steel tube and concrete. The results obtained from the FEM model were verified against experimental results. And comparison of mechanical behavior between CFST frame at ambient temperature and post fire was also analysised.(3) Typical examples of CFST composite frame were modeled using the FEM model. Parametric analysis was performed to investigate the mechanical behavior of the composite frame after exposure to fire. The strength of steel tube, the concrete strength of column, the steel ratio of column, slenderness ratio, the axial compression ratio, the depth of fire protection, the beam to colums linear stiffess ratio and the beam to column strength ratio were considered as parameters. The influence of parameters to the load to displacement curve of CFST composite frame after exposure to fire was received. A simplified P-Δcurve model was also given.更多还原