城市多龄期钢框架构件地震损伤模型及结构地震易损性研究

发布时间：2018-05-29 23:07

本文选题：多龄期 + 酸性大气　；参考：《西安建筑科技大学》2014年硕士论文

【摘要】：本文通过试验和数值模拟相结合的研究手段，对酸性大气环境下的城市多龄期钢框架的相关抗震性能评估方法进行了研究，其中包括：钢框架柱地震损伤模型研究和钢框架地震易损性研究。通过气雾腐蚀箱对城市酸性大气环境进行模拟，研究了钢材材料的力学性能在酸性大气环境下的退化规律，以及酸性大气环境下钢框架柱的地震损伤演化过程。通过变化加载方式、轴压比、锈蚀程度，对于12榀钢框架柱进行了低周反复加载试验，得出了钢框架柱的强度、刚度及耗能能力随着锈蚀程度、加载循环次数、加载方式及轴压比的变化规律；并通过相关试验数据的分析，得到钢框架柱的地震损伤演化规律，即：可分为损伤产生阶段、损伤稳定发展阶段和损伤剧烈发展阶段；进而，分析了随着试件锈蚀程度、轴压比、加载循环次数等参数的改变，对试件损伤发展产生的影响，为提出新的地震损伤模型提供了有效的试验支撑；针对已有的损伤模型的不足之处，，本文综合考虑了加载方式，加载路径，循环次数及屈服位移的变化，提出了一种新的地震损伤模型，并对相关参数进行了研究和说明。模型计算结果和试验研究结果的相互对比表明，该模型可较很好地描述试件在加载过程中的损伤发展情况；并依据相关研究提出了新的地震设防目标指数范围。本文根据酸性大气环境模拟下的钢材材性试验结果，结合城市既有的多龄期钢结构在实际酸性大气环境下的钢材锈蚀情况，得出了钢材材料相关力学性能随着钢结构龄期发展的退化规律。进而，基于该规律，利用ABAQUS有限元模拟软件，选用15条地震波进行了12次调幅，对城市酸性大气环境下服役龄期为0年、15年、30年、45年的四种钢框架，进行了增量动力时程分析；并采用层间位移角为性能准则，对钢框架进行了地震易损性研究。研究结果表明：在相同的地震动强度下，随着龄期的增大，钢框架结构超越某一极限状态的概率也随之增大。
[Abstract]:In this paper, the methods of seismic performance evaluation of urban multi-age steel frames under acidic atmosphere are studied by means of the combination of test and numerical simulation. It includes: seismic damage model of steel frame column and seismic vulnerability of steel frame. The degradation law of mechanical properties of steel materials in acidic atmosphere and the seismic damage evolution process of steel frame columns in acidic atmosphere were studied by simulating the urban acidic atmospheric environment by using the aerosol corrosion box. By changing loading mode, axial compression ratio and corrosion degree, 12 steel frame columns were subjected to low cycle repeated loading tests. The strength, stiffness and energy dissipation capacity of steel frame columns were obtained with corrosion degree and loading cycle times. Through the analysis of relevant test data, the law of seismic damage evolution of steel frame columns is obtained, which can be divided into three stages: damage generation stage, damage stable development stage and damage violent development stage. The influence of the parameters such as corrosion degree, axial compression ratio and loading cycle number on the damage development of the specimen is analyzed, which provides an effective test support for the proposed new seismic damage model. In view of the shortcomings of the existing damage models, this paper considers the changes of loading mode, loading path, cycle number and yield displacement, proposes a new seismic damage model, and studies and explains the relevant parameters. The comparison between the calculated results and the experimental results shows that the model can well describe the damage development of the specimens during the loading process, and a new range of seismic fortification target exponents is proposed based on the relevant studies. In this paper, according to the test results of steel material properties under the acidic atmospheric environment simulation, combined with the steel corrosion situation of the existing multi-age steel structures in the actual acidic atmosphere environment, The degradation law of the related mechanical properties of steel materials with the development of steel structure age is obtained. Then, based on this rule, using ABAQUS finite element simulation software, 12 amplitude modulations of 15 seismic waves are selected, and the incremental dynamic time history analysis is carried out for four steel frames with service ages of 0, 15, 30 and 45 years in the acidic atmosphere of the city. The seismic vulnerability of steel frame is studied by using interstory displacement angle as performance criterion. The results show that the probability of steel frame structure exceeding a certain limit state increases with the increase of age under the same ground motion intensity.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU391;TU312.3

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