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跨长度和时间尺度的工程材料的变形。该研究计划的长期目标是能够评估和增强三种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：核，航空航天和运输。这些行业中使用的材料经常在承载机械负载时暴露于敌对的环境中。在这种环境中，材料（弹性）或不可逆转地（塑料）变形。塑性变形可能会在工程组成部分的特定点上定位，然后导致裂纹成核和灾难性失败。 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。作为材料变形的本构模型，晶体可塑性可以进一步增强有限元素在研究变形定位机制方面的力量。数值研究通常需要进行开发和验证的实验观察。例如，电子或X射线显微镜可用于研究Nano和Meso量表的局部变形。 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，这些工具箱可以显着改善我们对变形的基本理解： i）开发一个依赖温度的非本地晶体可塑性有限元代码，用于建模由滑动带和双胞胎形成引起的塑性变形。该代码将能够模拟点缺陷和线路缺陷之间的相互作用。这是一种独特而新颖的能力，因为通过这种配方，可以研究由缺陷的扩散或线缺陷爬升产生的空隙。因此，该模型可用于研究和模拟多晶的蠕变，疲劳以及最终的断裂。 ii）开发一个世界领先能力，用于运行温度依赖性的原位高分辨率电子反向散射衍射和高分辨率数字图像相关技术。两种技术都是基于扫描电子显微镜的使用。它们可用于测量Nano，Meso和宏尺度的局部变形，因此可以验证将在（i）中开发的代码。 （i）和（ii）的立即应用在加拿大核工业中。随着Candu反应堆的衰老，辐射增强的蠕变已成为主要问题。这种变形模式是一种依赖时间的塑性变形，其建模主要是（i）的目标。这项研究的另一个应用是航空航天行业。钛和镍合金的蠕变和抗疲劳性是制造喷气发动机组件的两个主要因素。