Thermo-mechanical analysis of propagating instabilities in metals - from experiments to reliable numerical prediction

金属中传播不稳定性的热机械分析 - 从实验到可靠的数值预测

• 批准号: 527828607
• 负责人: Professor Dr.-Ing. Andreas Menzel
• 金额: --
• 依托单位: Institut für Mechanik (IM)
• 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/527828607?language=en
• 关键词: Thermo; mechanical; analysis; propagating; instabilities

Material instabilities significantly affect the respective metal’s properties such as ductility, strength and fatigue resistance. Typical examples of material instabilities in metals are phase-transition and localisation phenomena. The latter are in the focus of this proposal, namely propagating material instabilities in the form of Lueders bands and the Portevin-Le Chatelier (PLC) effect. The occurrence and evolution of such bands of plastic deformation, related to so-called strain aging, are known to depend on both strain rate and temperature. The understanding and reliable prediction of propagating Lueders and PLC bands are of key importance for resource-efficient design of components and structures made of materials showing these phenomena. This requires advanced thermo-mechanical models that capture the initiation and evolution of these bands at different loading rates and temperature levels on the one hand, and advanced experimental investigations in the context of parameter identification on the other. A unified model that captures the reliable and simultaneous prediction of Lueders bands and the PLC effect at different loading rates and temperature levels, and which is identified based on full field displacement and temperature data, is not available in the literature. The goal of this proposal is to fill this gap and to establish such model together with identification based on experiments including full field data.

材料的不稳定性会显著影响相应金属的性能，例如延展性、强度和抗疲劳性。金属材料不稳定性的典型例子是相变和局域化现象。后者是本提案的重点，即以Lueders带和Portevin-Le Chatelier（PLC）效应的形式传播材料不稳定性。已知与所谓的应变时效相关的这种塑性变形带的发生和演变取决于应变速率和温度。传播Lueders和PLC带的理解和可靠的预测对于由显示这些现象的材料制成的部件和结构的资源有效设计至关重要。这需要先进的热机械模型，捕捉这些带在不同的加载速率和温度水平的启动和演变，一方面，和先进的实验研究的参数识别的背景下。在文献中没有一个统一的模型，该模型捕获了在不同加载速率和温度水平下的Lueders带和PLC效应的可靠和同时预测，并且该模型是基于全场位移和温度数据识别的。本提案的目标是填补这一空白，并建立这样的模型与识别的基础上，包括全领域的数据实验。