Energy dissipation-based approach to stochastic fatigue of concrete considering interacting time and temperature effects

考虑相互作用的时间和温度效应的基于能量耗散的混凝土随机疲劳方法

• 批准号: 471796896
• 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
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/471796896?language=en
• 关键词: Energy; dissipation; based; approach; stochastic

The need to drastically reduce material consumption and increase the service life of engineering structures urgently requires higher material utilization, accompanied with intelligent maintenance, repair and recycling concepts. The overall objective of the research proposal is to support the necessary innovative development in structural concrete design by deepening the knowledge of the material and structural behavior in the whole range of interacting loading and environmental attack scenarios during the structure’s lifetime. While high-cycle fatigue of metals has been thoroughly studied and scientific results have progressed to engineering practice by providing reliable predictions of fatigue lifetime, the fatigue damage propagation mechanisms in concrete are yet to be fully understood. In spite of a remarkable progress in recent years made in modeling and characterizing the concrete fatigue behavior, many open questions remain that need to be fundamentally addressed in order to develop a deep and general insight into the phenomenology of concrete fatigue. The scientific goal of the research is to develop advanced, thermodynamically consistent numerical modeling approaches and characterization methods that can capture the interplay of dissipative mechanisms governing fatigue behavior on a broader basis than currently possible. To achieve this goal, the existing common meso-macro modeling platform, which reflects fatigue behavior in terms of local cumulative strain evolution, will be extended to include the influence of temperature, loading rate, and time-dependent material changes. The theoretical and numerical developments will be validated by a systematic experimental program providing multiple observation perspectives to the studied phenomena. To maximize the relevance of the research for engineering practice, the randomness inherent to fatigue loading and local material properties will be captured using advanced methods of probabilistic modeling that will be used for statistical characterization of fatigue behavior in terms of S-N curves, fatigue crack propagation criteria, effect of loading sequence and fatigue creep development. This characterization will serve as a basis for refined design and assessment rules in engineering codes.

需要大幅度减少材料消耗并迫切需要更高的工程结构的使用寿命，需要更高的物料利用，并伴有智能维护，维修和回收概念。研究建议的总体目的是通过加深对结构一生中整个相互作用的负载和环境攻击场景的材料和结构行为的了解来支持结构混凝土设计中必要的创新发展。尽管金属的高周期疲劳已经进行了彻底研究，并且科学的结果通过提供可靠的疲劳寿命预测来发展到工程实践，但混凝土中疲劳损伤的传播机制尚待充分了解。尽管近年来在建模和表征具体疲劳行为方面取得了显着进展，但仍需要解决许多开放问题，以便对混凝土疲劳的现象有深入而一般的见解。该研究的科学目标是开发高级，热力学上一致的数值建模方法和表征方法，这些方法可以捕获比当前更广泛的疲劳行为的耗散机制的相互作用。为了实现这一目标，现有的常见中摩麦建模平台将扩展到局部累积应变演化方面，该平台将扩展到包括温度，加载速率和时间相关的材料变化的影响。理论和数值的发展将通过系统的实验程序来验证，该程序为研究造成的现象提供了多种观察角度。为了最大程度地提高工程实践研究的相关性，将使用先进的概率建模方法来捕获疲劳载荷和局部材料特性所固有的随机性，该方法将用于S-N曲线，疲劳裂纹式传播标准，负载序列和疲劳蠕变的效果。这种表征将作为工程代码中精制设计和评估规则的基础。