Fatigue of structural concrete driven by a cumulative measure of shear strain

由剪切应变累积测量驱动的结构混凝土疲劳

• 批准号: 412131890
• 负责人: Professor Dr. Rostislav Chudoba
• 金额: --
• 依托单位: Lehrstuhl und Institut für Massivbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/412131890?language=en
• 关键词: Fatigue; structural; concrete; driven; cumulative

The major objective of the project is to develop a consistent theoretical, numerical and experimental framework for analysis and characterization of fatigue behavior of concrete. The framework will provide the basis for a deeper understanding of damage mechanisms driving the fatigue propagation of in concrete at subcritical levels of loading. The improved reflection of the fatigue phenomenology compared to the state-of-the-art methods will reduce the number of expensive experiments needed for reliable characterization of high cycle fatigue response. The goal of the theoretical and numerical development is to establish a multi-scale modeling framework based on thermodynamically consistent representation of the dissipative mechanisms associated with cumulative cyclic deformation at subcritical levels of loading. By capturing the key dissipative mechanisms, we will be able to significantly enhance the validity and efficiency of fatigue models for concrete structures. The strategy will consistently combine discrete models of the material structure at the mesoscale and macroscopic phenomenological models of the microplane type. At the same time, it will introduce the possibility to devise an accelerated time integration scheme for an efficient simulation of high-cycle fatigue response. The proposed multi-scale modeling strategy will stimulate the development of a systematic calibration and validation methodology consisting of a sequence of elementary test setups. Systematic test methods will be deployed with the goal to isolate particular effects of fatigue behavior of concrete in order to uncover and describe their relation to the postulated elementary dissipative mechanisms. The ambition of this development is to provide a sound explanation of still puzzling fatigue phenomena, like the fundamentally different fatigue behavior of concrete under tensile and compressive cyclic loading with variable amplitudes.In comparison to the state-of-the-art methods of fatigue characterization, the proposed approach will establish the basis for more efficient characterization and assessment of fatigue behavior of reinforced concrete. In the long run, the developed methods will contribute to formulation of reliable and economic design concepts and codes for structural concrete exposed to fatigue loading. The proposed research project will combine expertise of the two partner teams in different disciplines. In particular, discrete, mesoscale modeling and efficient time-integration along the lifetime domain will be the focus of the team at Brno University. The macroscopic, phenomenological modeling and experimental methods will be developed at RWTH Aachen University.

该项目的主要目标是建立一个一致的理论、数值和实验框架，用于分析和表征混凝土的疲劳行为。该框架将为更深入地理解混凝土在亚临界荷载水平下疲劳扩展的损伤机制提供基础。与最先进的方法相比，疲劳现象学的改进反映将减少可靠地表征高周疲劳响应所需的昂贵实验的数量。理论和数值发展的目标是建立一个多尺度模拟框架，其基础是亚临界载荷水平下与累积循环变形相关的耗散机制的热力学一致性表示。通过捕捉关键的耗散机制，我们将能够显著提高混凝土结构疲劳模型的有效性和效率。该战略将始终如一地将中尺度材料结构的离散模型与微平面类型的宏观唯象模型结合起来。同时，还介绍了为高效模拟高周疲劳响应而设计加速时间积分方案的可能性。拟议的多尺度建模战略将促进由一系列基本测试设置组成的系统校准和验证方法的发展。将部署系统的测试方法，目的是隔离混凝土疲劳行为的特殊影响，以揭示和描述它们与假定的基本耗散机制的关系。这一发展的目的是为仍然令人费解的疲劳现象提供合理的解释，例如混凝土在不同幅值的拉伸和压缩循环荷载下的疲劳行为根本不同。与最先进的疲劳表征方法相比，所提出的方法将为更有效地表征和评估钢筋混凝土的疲劳行为奠定基础。从长远来看，所开发的方法将有助于制定可靠和经济的结构混凝土疲劳荷载设计概念和规范。拟议的研究项目将结合两个伙伴团队在不同学科的专业知识。特别是，离散的中尺度建模和生命周期领域的有效时间积分将是布尔诺大学团队的重点。宏观的、现象学的建模和实验方法将在RWTH亚琛大学开发。