7075高强铝合金管约束混凝土柱轴压承载力计算

CALCULATION ON BEARING CAPACITY OF 7075 HIGH-STRENGTH ALUMINUM ALLOY TUBULAR CONFINED CONCRETE COLUMN UNDER AXIAL COMPRESSION

高强铝合金由于具有耐腐蚀、强度高、延性好等优点,在大型基础设施工程中具有十分广阔的应用前景。在对比分析钢管约束混凝土柱轴压承载力常用计算理论的基础上,提出了铝合金管约束混凝土柱承载力计算方法,应用有限元程序ABAQUS对7075高强铝合金管约束混凝土柱的轴压性能进行了数值模拟计算,并将有限元模拟计算结果与理论分析结果进行了对比。研究结果表明:欧洲标准(EC4)没有考虑钢管对混凝土的约束作用,故所得计算承载力值偏于安全;"统一理论"矩形钢管计算式并不适用于铝合金约束混凝土矩形柱;而按DL/T 5085—1999《钢-混凝土组合结构设计规程》和GJB 4142—2000《战时军港抢修早强型组合结构技术规程》所得的铝合金管约束混凝土柱承载力比有限元模拟值仅高出4%左右,计算结果与理论分析吻合较好。最后基于DL/T 5085—1999和GJB 4142—2000,以约束效应系数为参数,提出了铝合金管约束混凝土柱轴压承载力计算方法。

High-strength aluminum alloy has great application prospects in large-scale infrastructure projects due to its corrosion resistance,high strength and good ductility. In this paper,based on the comparative analysis of the commonly used calculation theory of bearing capacity of confined concrete columns under axial compression,the calculation method of bearing capacity of aluminum alloy tubular confined concrete columns was proposed. Then,the finite element model of 7075 high-strength aluminum alloy tubular confined concrete column under axial compression was established by ABAQUS. The finite element simulation results were compared with the calculation results based on the existing experimental results of aluminum alloy tubular confined concrete column. The results showed that the Eurocode 4 did not take the restraint factor of steel pipe on concrete into account,which led to the calculated result biased towards a safe value. The "unified theory "rectangular steel tube calculation formula did not suitable for aluminum alloy confined concrete rectangular column. According to Code for Design of Steel-Concrete composite Structure (DL/T 5085-1999) and Technical specifications for Early-Strength Model Composite Structure Used for Nary Port Emergency Repair in Wartime (GJB 4142-2000),however,the obtained bearing capacity of aluminum alloy tubular confined concrete column was only about 4 percent higher than the finite element simulation value which indicated the finite element simulation results were consistent with the test results. Finally,based on DL/T code and GJB code while treating the constraint effect coefficient as the parameter,the calculation method of axial compressive capacity of concrete column restrained by aluminum alloy tube was proposed.