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类型 基础研究 预答辩日期 2018-05-17
开始(开题)日期 2013-12-30 论文结束日期 2018-02-26
地点 九龙湖土木科研楼214 论文选题来源 国家自然科学基金项目     论文字数 10 (万字)
题目 钢筋混凝土氯离子侵蚀与锈胀致裂过程耦合分析方法研究
主题词 过程耦合,氯离子侵蚀,混凝土损伤,细观混凝土模型,耐久性
摘要 氯离子环境下钢筋混凝土的耐久性是海工结构中面临的突出问题。氯离子侵蚀混凝土会导致钢筋发生锈蚀,钢筋锈蚀体积膨胀会导致混凝土保护层的开裂,进而会显著改变氯离子在混凝土中的输运通道,进一步加剧钢筋锈胀破坏过程。因此,氯离子侵入与钢筋锈蚀膨胀导致混凝土开裂是相互耦合、渐进加强的非线性过程。针对这一耦合问题开展数值方法及模拟技术研究具有重要的理论意义和广泛的工程应用前景。 本文围绕氯离子侵入与钢筋锈胀致裂的过程耦合分析方法、全自动分析过程的实现,以及钢筋混凝土耐久性破坏过程等方面开展了深入研究,主要创新性工作及成果如下: (1) 提出了过程耦合分析方法。该方法针对氯离子侵蚀混凝土和钢筋锈胀导致混凝土开裂破坏这两类不同的物理和力学过程,通过动态数据的交换和控制,以及模型的全自动化生成和更新,实现了两类过程的耦合求解。借助于ABAQUS软件平台,通过编写用户子程序和接口程序,实现了所提出的过程耦合分析方法。利用试验数据,验证了耦合分析方法的正确性和高效性。 (2) 建立了钢筋锈蚀膨胀过程的力学等效转换方法。针对钢筋锈蚀体积膨胀这一化学过程,给出了通过膨胀位移加载、膨胀温度加载,以及动态温度线膨胀系数加载三种方式实现力学等效转换过程。通过仿真分析,讨论了这三种力学等效转换方法的优劣点及其使用的分析过程。 (3) 开展了非均质时变扩散与细观混凝土损伤演化的联合求解技术。借助于建立的过程耦合分析方法,采用Python及Fortran语言,对ABAQUS软件进行二次开发,实时更新氯离子扩散问题中的非均质时变扩散系数,解决了包含界面过渡区(ITZ)信息的混凝土细观模型的全自动建模,针对氯离子侵蚀细观钢筋混凝土问题,实现了从不同组份材料的细观损伤,到构件层次的耐久性失效的全过程分析。 (4) 提出了面向海工钢筋混凝土结构设计的新思路。针对海工钢筋混凝土暴露于高浓度氯离子环境下的特点,利用提出和发展的过程耦合分析方法,对结构设计中的钢筋间距、钢筋直径以及配筋率等关键性参数进行了敏感性分析,从理论上解释了海洋及近海钢筋混凝土结构过早失效现象。建议海工钢筋混凝土结构设计中应该考虑过程耦合作用,统筹结构的承载力和耐久性两方面,合理设计结构中的配筋。 论文的研究工作丰富和发展了钢筋混凝土结构耐久性研究中的基本方法,为海工钢筋混凝土结构的设计提供了新的分析手段。
英文题目 Study on Coupling Analysis Method of Chloride Erosion and Corrosion Expansion in Reinforced Concrete
英文主题词 process coupling,chloride ions erosion,concrete damage,meso-concrete model, durability
英文摘要 Chloride ions erosion is a prominent problem on the durability of marine reinforced concrete structures. Chloride penetrating to the inner of concrete lead to the steel corrosion and the volume expanding of steel corrosion product causes concrete protective layer cracking, which significantly affects the transfer path of chloride ions in concrete, thus further aggravate the steel corrosion. Therefore the penetration of chloride ions as well as the erosion of rebar in concrete are two nonlinear mutually strengthening and coupling processes. It is of great theoretical significance and a promising prospect in engineering practice to research on numerical method and simulation technology for the coupling problem. This paper thoroughly studies on the process coupling analysis method for chloride ions erosion and concrete damage caused by steel corrosion, the realization of automatic analysis process and the damaging process of reinforced concrete structure. The main innovative work and results are as follows: (1) The process coupling analysis method is proposed. The chloride ions erosion and the evolution of concrete damage are the different physical and mechanical processes. In this paper, the coupled solution is realized by exchanging and controlling the dynamic data between the different process, as well as fully automated generation and updating models. With ABAQUS software platform, the proposed method is realized by programming user subroutine and interface program. Using the experimental data, the correctness and efficiency of the proposed method are verified. (2) For the steel corrosion expansion, the mechanics equivalent method is established. three loading methods are used to simulate the volume expanding of non-uniform steel corrosion, including the equivalent displacement loading, the equivalent node temperature loading and the dynamic temperature linear expansion coefficient loading. The advantages and disadvantages of the three mechanics equivalent methods and their applicable analysis process are discussed. (3) In the meso-concrete, the coupling method between the heterogeneous time-varying diffusion and the damage evolution process is developed. Based on the proposed method, the secondary development of ABAQUS software in Python and Fortran language is carried out to update the heterogeneous time-varying diffusion coefficient in real time. And this program solve the fully automated modeling of meso-concrete with interface transition zone (ITZ). For the chloride ions erosion into the meso-concrete, the established method realizes the complete analysis from the different materials damage in the meso-scale to the concrete members failure. (4) A new idea for design of marine reinforced concrete structures is presented. According to the characteristics of marine reinforced concrete exposed to high chloride ions environment, the sensitivity analysis of the key parameters in structural design was made by the developed process coupling analysis method, such as reinforcement spacing, reinforcement diameter, reinforcement ratio and so on. The analysis results theoretically explain the premature failure of marine reinforced concrete structures. It is suggested that the reinforcement should be combined with structural bearing capacity and durability in the design of marine reinforced concrete structures. This paper enriches and develops the basic methods in the durability of reinforced concrete structures. and it provides a new analytical method for the design of marine reinforced concrete structures.
学术讨论
主办单位时间地点报告人报告主题
郭力教授课题组 2012.6.11 逸夫馆607 张 芹 氯离子影响钢筋混凝土结构耐久性研究
郭力教授课题组 2016.12.1 逸夫馆607 张芹 氯离子环境下钢筋锈蚀膨胀与扩散耦合研究
土木工程学院 2012.5.3 榴园宾馆新华 Zdenek P. Bazant Pervasiveness of Concrete Creep Problem in Structures: Wake-Up Call for Design Code and Consequences of Nano-Porosity
郭力教授课题组 2012.11.14 逸夫馆607 张芹 钢筋混凝土物理非线性
郭力教授课题组 2013.11.22 逸夫馆607 张芹 The Structural Materials Development
郭力教授课题组 2016.4.19 逸夫馆607 张芹 钢筋混凝土氯离子侵蚀与锈胀致过程耦合分析方法研究
土木工程学院 2016.12.12 逸夫楼1501大会议室 尹顺德 Finite Element Modeling of Thermal Fracturing in Subsurface Injection Processes
土木工程学院 2017.6.5 逸夫馆15楼会议室 Ming L. Wang VOTERS-A platform for continuous network- wide health monitoring of roadways
     
学术会议
会议名称时间地点本人报告本人报告题目
Southeast University 2013.9.23-2013.9.25 Nanjing Analysis of Chloride Heterogeneous Migration in Concrete with Time-space Consistent Collocation Method
Queensland University of Technology 2015.11.30-2015.12.1 Brisbane Coupling effects of chloride penetrating and corrosion damage evolving process in concrete under marine environment
     
代表作
论文名称
混凝土中氯离子非均质扩散问题时空一致径向基函数配点法
氯离子侵蚀下钢筋混凝土非线性锈胀破坏过程模拟
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
章青 正高 教授 博导 河海大学
邵建国 正高 教授 博导 河海大学
史治宇 正高 教授 博导 南京航空航天大学
郭小明 正高 教授 博导 东南大学
张云升 正高 教授 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
孙宾 其他 讲师 东南大学