Deformation of Engineering Materials Across length and time Scales (DEMAS)

工程材料在长度和时间尺度上的变形 (DEMAS)

• 批准号: RGPIN-2017-04969
• 负责人: Abdolvand, Hamidreza
• 金额: $ 1.75万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711322
• 关键词: Deformation; Engineering; Materials; Across; length

The proposed program aims to study deformation of engineering materials across length and time scales. The long term objective of this research program is to be able to assess and enhance structural integrity and performance of the metallic and non-metallic composites used in three strategic industries: nuclear, aerospace, and transportation. The materials that are used in these industries are very often exposed to hostile environments while carrying mechanical loads. In such environments, materials deform reversibly (elastically) or irreversibly (plastically). Plastic deformation can potentially localize at particular points in engineering components and subsequently lead to crack nucleation and catastrophic failure. Finite element is a powerful numerical technique that can be used for simulating elastic and plastic deformation of materials. Crystal plasticity, as a constitutive model for materials' deformation, can further enhance the power of finite element to study mechanisms of deformation localization. Numerical studies often require experimental observations for both development and validation. For instance, electron or X-ray microscopy can be used to study localized deformation at nano and meso scales. The aim of this program is to characterize, formulate, and simulate localized plastic deformation; the applicant proposes to develop three numerical and experimental toolboxes that can significantly improve our fundamental understanding of deformation: I) Developing a temperature dependent non-local crystal plasticity finite element code for modelling plastic deformation caused by formation of slip bands and twins. The code will be able to simulate interaction between point defects and line defects. This is a unique and novel capability as through such formulation, void formation resulting from diffusion of defects or climb of line defects can be studied; hence, the model can be used to study and simulate creep, fatigue, and eventually fracture of polycrystals. II) Developing a world leading capability for running temperature dependent in-situ High Resolution Electron BackScatter Diffraction and High Resolution Digital Image Correlation techniques. Both techniques are based on the use of scanning electron microscopes; they can be used for measuring localized deformation at nano, meso, and macro scales and hence validate the code that will be developed in (I). The immediate application of (I) and (II) is in the Canadian nuclear industry. With the aging of CANDU reactors, irradiation enhanced creep has become a major concern. This mode of deformation is a time dependent plastic deformation the modelling of which is the primarily goal of (I). Another application of this research is in the aerospace industry. Creep and fatigue resistance of titanium and nickel alloys are the two main factors in manufacturing jet engines components.

拟议的计划旨在研究工程材料在长度和时间尺度上的变形。该研究计划的长期目标是能够评估和增强核、航空航天和交通运输三个战略行业中使用的金属和非金属复合材料的结构完整性和性能。这些行业中使用的材料在承受机械负载的同时经常暴露在恶劣的环境中。在这种环境中，材料会发生可逆（弹性）或不可逆（塑性）变形。塑性变形可能集中在工程部件的特定点，随后导致裂纹成核和灾难性故障。 有限元是一种强大的数值技术，可用于模拟材料的弹性和塑性变形。晶体塑性作为材料变形的本构模型，可以进一步增强有限元研究变形局部化机制的能力。数值研究通常需要实验观察来进行开发和验证。例如，电子或 X 射线显微镜可用于研究纳米和介观尺度的局部变形。 该程序的目的是表征、制定和模拟局部塑性变形；申请人建议开发三个数值和实验工具箱，可以显着提高我们对变形的基本理解： I) 开发温度相关的非局部晶体塑性有限元代码，用于模拟由滑移带和孪晶形成引起的塑性变形。该代码将能够模拟点缺陷和线缺陷之间的相互作用。这是一种独特而新颖的功能，因为通过这种公式，可以研究由于缺陷扩散或线缺陷攀爬而导致的空洞形成；因此，该模型可用于研究和模拟多晶的蠕变、疲劳和最终断裂。 II) 开发世界领先的运行温度相关原位高分辨率电子背散射衍射和高分辨率数字图像相关技术的能力。这两种技术均基于扫描电子显微镜的使用。它们可用于测量纳米、细观和宏观尺度的局部变形，从而验证将在 (I) 中开发的代码。 (I) 和 (II) 的直接应用是加拿大核工业。随着CANDU反应堆的老化，辐照增强蠕变已成为一个主要问题。这种变形模式是一种与时间相关的塑性变形，其建模是 (I) 的主要目标。这项研究的另一个应用是在航空航天业。钛和镍合金的抗蠕变性和抗疲劳性是制造喷气发动机部件的两个主要因素。