Visualisation and micromechanical modelling of internal damage processes due to cyclically loaded high performance concretes, with emphasis on the hygral and thermal boundary conditions

循环加载高性能混凝土造成的内部损伤过程的可视化和微机械建模，重点关注湿和热边界条件

• 批准号: 353981539
• 负责人: Professor Dr.-Ing. Frank Dehn
• 金额: --
• 依托单位: Institut für Werkstoffe im Bauwesen
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/353981539?language=en
• 关键词: Visualisation; micromechanical; modelling; internal; damage

Main objective of the proposed project is to develop experimental and virtual numerical methods that enable the assessment of materials degradation in high performance concrete under fatigue loading. The research work will be conducted by an interdisciplinary research network with a clear task structure and an open data exchange among the complex degradation phenomena. For achieving the greatest possible knowledge gain, the sub-projects will take place within the context of a multi-scale approach, with a clear focus on the selected high performance concretes and most dominant impacts. Result of the research will be a method to assess the damage processes of high performance concrete while under tensile and/or flexural loading with a simultaneous consideration of the hygral/thermal boundary conditions. As first approach, two high-performance concretes will be defined that allow for a direct comparison of the individual material-specific damage influences and how they affect the changes in the microstructure cyclic behavior. In addition, during the cyclic tensile and/or flexural loaded tests, the alterations in material behavior will be detected by a continuous photogrammetry system which is mounted at the surface of the loaded specimens. Based on these results, SN curves will be created that are taking into account the applied relative stress/strength difference as well as the lowest stress/strength level applied to the specimens. Furthermore, a comparative study of both the unloaded and cycled loaded specimens will be carried out using a combination of different imaging techniques, such as microXCT-scanner and other indirect analysis methods. In this, particular attention will be given to the influence hygral and thermal boundary conditions have on the microstructural changes due to cyclic loading. For further analysis of the obtained experimental data an open structured online database will be developed. This will be part of a virtual laboratory with defined ontology that can be used for analysis of cyclic induced damage processes in high performance concretes. As part of the multi-scale modeling activities, simulated results validated by the conducted experimental tests will be the first building blocks of the object-oriented virtual lab environment.

拟议项目的主要目的是开发实验性和虚拟数值方法，以评估疲劳载荷下高性能混凝土中材料降解的评估。研究工作将由跨学科研究网络进行，该研究网络具有清晰的任务结构和复杂降解现象之间的开放数据交换。为了实现最大的知识收益，子项目将在多尺度方法的背景下进行，并明确关注所选的高性能混凝土和最主要的影响。研究的结果将是一种评估在拉伸和/或弯曲负载下以及同时考虑hygral/hygral/热边界条件下的高性能混凝土损伤过程的方法。作为第一种方法，将定义两种高性能混凝土，以直接比较单个材料特定的损伤影响以及它们如何影响微结构循环行为的变化。另外，在循环拉伸和/或弯曲载荷测试期间，将通过安装在加载样品表面的连续摄影测量系统检测物质行为的改变。基于这些结果，将创建SN曲线，这些曲线正在考虑到所应用的相对应力/强度差以及应用于样品的最低应力/强度水平。此外，将使用不同成像技术的组合（例如Microxct-Scanner和其他间接分析方法）进行对卸载和循环载荷标本的比较研究。在此中，将特别关注潮流和热边界条件对循环载荷引起的微结构变化的影响。为了进一步分析获得的实验数据，将开发开放结构化的在线数据库。这将是具有定义本体论的虚拟实验室的一部分，该实验室可用于分析高性能混凝土中环状诱导的损伤过程。作为多尺度建模活动的一部分，通过执行实验测试验证的模拟结果将是面向对象的虚拟实验室环境的第一个构建块。