Buildup of anamnesis and swept out of memory under coupling of monotonic and cyclic loading

在单调和循环加载的耦合下建立回忆并清除内存

• 批准号: 396461881
• 负责人: Professor Dr.-Ing. Theodoros Triantafyllidis
• 金额: --
• 依托单位: Lehrstuhl für Bodenmechanik, Grundbau u Umweltgeotechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/396461881?language=en
• 关键词: Buildup; anamnesis; swept; out; memory

The aim of this project is to develop a method to couple a cyclic explicit constitutive model inparallel with a non-linear monotonic material model. The evolution of the historiotropic state variables used by both the monotonic and the cyclic models should be described by this coupling. These evolution equations should allow the buildup of material memory (anamnesis) and/or its degradation depending on the loading conditions. The mechanical soil behavior is strongly influenced by the loading history (i.e. stress/strain path dependency). The soil adapts its internal structure to the applied loads and each load change causes a reorganization of force chains in the soil skeleton. This reorganization can be regarded as some kind of buildup or degradation of memory. The evolution laws of this memory should be captured by the coupling model in the context of this research project. By way of example of the coupling, the hypoplastic and the HCA models are combined into a single constitutive equation, in which monotonic and cyclic loads can be simultaneously treated. In addition to the simultaneous (parallel) application of monotonic and cyclic loads, this coupling can describe the sequential (serial) alternation of monotonic and cyclic loads. By means of element tests the influence of different preloading (monotonic or cyclic) conditions on the evolution of the historiotropic variables can be studied and the required parameters calibrated. The predictive and explanatory potential of this coupling as well as the robustness of its numerical implementation should be demonstrated with the help of a finite element simulation of an exemplary boundary value problem.

本计画的目的是发展一种将循环显式本构模型与非线性单调材料模型并行耦合的方法。单调模型和循环模型所用的各向同性状态变量的演化都可以用这种耦合来描述。这些演化方程应允许材料记忆（记忆）的建立和/或其退化取决于加载条件。土壤的力学行为受荷载历史（即应力/应变路径依赖性）的强烈影响。土壤使其内部结构适应所施加的载荷，每次载荷变化都会导致土壤骨架中力链的重组。这种重组可以被看作是某种记忆的积累或退化。在本研究项目的背景下，这种记忆的演变规律应该被耦合模型捕获。通过耦合的例子，亚塑性和HCA模型合并成一个单一的本构方程，其中单调和循环载荷可以同时处理。除了单调和循环载荷的同时（并行）应用，这种耦合可以描述单调和循环载荷的顺序（串行）交替。通过单元试验，可以研究不同的预加载（单调或循环）条件对历史变量演变的影响，并校准所需的参数。这种耦合的预测和解释的潜力，以及其数值实现的鲁棒性，应证明与一个示例性的边界值问题的有限元模拟的帮助。