摘要
腐蚀将改变钢材的化学和物理特性,使得构件性能退化,严重影响结构的抗震性能。为此,该文首先通过重庆地区年降雨时间建立了混合概率模型,将该混合模型与酸雨对金属的腐蚀特点相结合给出了三种不同方式的腐蚀模型。然后,利用腐蚀模型对14个足尺Q345等边角钢试件和25个材性试件展开了不同方式和不同时间的腐蚀,并由材性试验结果对Q345钢力学性能参数的变化规律进行分析和建模。最后,通过拟静力试验,研究了腐蚀环境对Q345等边角钢构件破坏模式、滞回曲线以及主要抗震性能评价参数的影响规律,建立了与之对应的退化模型。结果发现:1)材性性能随腐蚀损伤增加而退化,甚至出现屈服点消失;2)承载力的试验值和理论值均因腐蚀损伤而降低,但规范计算公式并不能有效考虑腐蚀损伤;3)腐蚀损伤使得往复加载次数和滞回环面积减少,刚度退化幅值显著减小,延性和耗能能力降低。
As chemical and physical properties of members were changed by corrosion, the aseismic behavior of a structure was degenerated. Therefore, a mixture distribution model was derived by taking annual rainfall records in Chongqing as an object firstly. Three different corrosion modes of acid rain were proposed by combined with this mixture distribution model and metal corrosion characteristics. Then, there were 14 full-scale Q345 equal-angles and 25 material specimens were corroded by different corrosion modes and corrosion periods. Through the results of a material test, the variation law of the mechanical properties of Q345 steel was discussed, and those corresponding mathematical expressions with a corrosion damage were also proposed. At last, through a quasi-static test, the failure modes and hysteretic curves of Q345 equal-angles were obtained, and the main parameters for estimating the earthquake resistant behavior of Q345 equal-angles were also studied, such as load-carrying capacity, ductility ratio, stiffness degenerated and energy dissipation coefficients. It can be found that: 1) the mechanical property was degenerated with corrosion damages, even the yield point was disappeared. 2) the experimental and theoretical values of load-carrying capacity were all decreased with corrosion damages. However, the corrosion damage could not be calculated by the formula of current steel structural code. 3) as the cycles and area of hysteresis loops were decreased, the parameters for estimating earthquake resistant behaviors were influenced evidently by corrosion damages.
出处
《工程力学》
EI
CSCD
北大核心
2014年第11期53-62,共10页
Engineering Mechanics
基金
国家自然科学基金项目(50908243)
重庆市自然科学基金项目(CSTC
2009BB4191)
关键词
腐蚀环境
Q345等边角钢
抗震性能
材性性能
混合模型
拟静力试验
environment corrosion
Q345 equal angles
seismic behavior
mechanical properties
mixture distribution modes
quasi-static test
