近海大气环境下在役钢框架结构地震损伤性能及易损性研究

发布时间：2018-03-30 02:23

本文选题：多龄期　切入点：近海大气　出处：《西安建筑科技大学》2015年硕士论文

【摘要】：本文采用试验研究和有限元数值分析相结合的方法,对近海大气环境下在役钢框架结构的耐久性和相关抗震性能进行了研究,其中包括:锈蚀平面钢框架结构拟静力试验研究、钢结构地震损伤模型研究和多龄期钢结构地震易损性研究。具体研究围绕以下几个方面开展:(1)通过模拟近海大气环境对钢结构试件进行腐蚀,并对具有不同锈蚀程度的4榀缩尺平面钢框架结构试件及63个标准钢材材性试件分别进行了低周往复循环加载试验和材性拉伸实验,得到基于结构层面的试件整体和各层的承载能力、强度、刚度和耗能能力的退化规律和基于材料层面的钢材力学性能的退化规律。填补了国内外基于结构层面的耐久性研究的空白。(2)对不同锈蚀程度的平面钢框架结构进行ABAQUS有限元数值模拟计算,并与试验结果对比分析,发现两者的破坏形态基本一致,试件的承载力、耗能能力及延性系数的退化接近,最终的破坏模式也完全吻合。验证了通过考虑材料“名义”力学性能退化进行的锈蚀钢结构有限元分析方法,能够较为真实地反映试件的实际承载能力退化过程。(3)在现有地震损伤模型研究成果的基础之上,基于最大变形(层间位移)的损伤模型,引入耗能参数,提出能够同时反映最大变形效应和累积损伤效应的双参数整体地震损伤模型。(4)通过有限元分析软件建立不同锈蚀程度的平面钢框架结构模型,利用非线性静力推覆分析,得到结构的整体初始刚度K0随着锈蚀程度增大的退化规律,并将此规律引入本文提出的双参数结构整体地震损伤模型当中,得到适用于锈蚀钢结构的“时变”损伤模型;以基于变形和耗能的损伤模型以及双参数整体“时变”损伤模型作为结构性能指标,以PGA作为地震动强度指标,对多龄期钢框架结构进行易损性分析,对比了不同龄期下采用不同损伤指标表征的结构易损性曲线的变化规律。
[Abstract]:In this paper, the durability and seismic behavior of existing steel frame structures in offshore atmosphere are studied by means of the combination of experimental research and finite element numerical analysis, including the quasi-static test of corroded plane steel frame structures. Study on seismic damage model of steel structure and seismic vulnerability of multi-age steel structure. Concrete research is carried out around the following several aspects: corrosion of steel structure specimen by simulating offshore atmospheric environment. The low cycle cyclic loading test and the material tensile test were carried out on 4 steel frame specimens with different corrosion degrees and 63 standard steel specimens. The load-carrying capacity and strength of the whole specimen and each layer based on the structural layer are obtained. The degradation law of stiffness and energy dissipation capacity and the degradation law of mechanical properties of steel based on material layer filled the blank of durability research based on structural layer at home and abroad. ABAQUS finite element numerical simulation, Comparing with the test results, it is found that the failure patterns of the two specimens are basically the same, and the degradation of the bearing capacity, energy dissipation capacity and ductility coefficient of the specimens are close to each other. The ultimate failure mode is in good agreement. The finite element analysis method of corroded steel structure is verified by considering the degradation of the material's "nominal" mechanical properties. Based on the research results of existing seismic damage models and based on the damage model of maximum deformation (interstory displacement), energy dissipation parameters are introduced. A two-parameter integral seismic damage model, which can reflect both the maximum deformation effect and cumulative damage effect, is proposed. The finite element analysis software is used to establish the plane steel frame structure model with different corrosion degree, and the nonlinear static push-over analysis is used. The degradation law of the initial stiffness K _ 0 of the whole structure with the increase of corrosion degree is obtained, and the law is introduced into the global seismic damage model of the two-parameter structure proposed in this paper, and a "time-varying" damage model suitable for corroded steel structure is obtained. The damage model based on deformation and energy dissipation and the "time-varying" damage model with two parameters as structural performance index and PGA as ground motion intensity index are used to analyze the vulnerability of multi-age steel frame structure. The changes of vulnerability curves of structures characterized by different damage indexes at different ages were compared.
【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】：2015
【分类号】：TU391;TU352.11

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