Investigation of local features and mechanisms that lead to global failure in heterogeneous materials

研究导致异质材料整体失效的局部特征和机制

• 批准号: 217013-2013
• 负责人: Pilkey, Keith
• 金额: $ 1.6万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=546500
• 关键词: Investigation; local; features; mechanisms; lead

The proposed research program seeks to provide a better understanding of how materials fail. The internal structure of many materials is non-uniform, ie. heteregeneous, which means that failure is likely to initiate at a location (or several locations) where the structure and/or material properties are weaker. The basic premise behind the current study is to use a unique micro-computed tomography (microCT) facility at Queen's University to acquire a sequence of three-dimensional images of the internal structure of hetergeneous materials as they are being deformed. These images will provide invaluable insight into the role of internal structure in initiating material failure. Two distinctly different types of heterogenous materials will be examined: metal alloys and cancellous (or trabecular) bone. In metal alloys, the key features of interest in the microCT images are small voids that initiate and grow as the material is deformed; they eventually link together to cause catastrophic failure. In cancellous bone, the internal structure is made up of a three-dimensional network of struts (trabeculae) and plates, where failure is first triggered by the buckling and/or fracture of individual trabeculae. The ultimate goal of this research will be to characterize the physical characteristics of these failure initiation sites to see if a common weakness in the local structure can be found for each of the two materials under study. Furthermore, the progression of failure from one or more locally contained regions to a more global scale is also of great interest in predicting material failure.

拟议的研究计划旨在更好地了解材料如何失效。 许多材料的内部结构是不均匀的，即。非均匀性，这意味着故障可能在结构和/或材料性能较弱的位置（或几个位置）开始。 当前研究背后的基本前提是使用女王大学独特的微型计算机断层扫描（microCT）设施来获取非均质材料变形时内部结构的三维图像序列。 这些图像将提供宝贵的洞察内部结构在启动材料故障的作用。 将检查两种明显不同类型的异质材料：金属合金和松质骨（或小梁骨）。 在金属合金中，microCT图像中感兴趣的关键特征是随着材料变形而产生和生长的小空隙;它们最终连接在一起导致灾难性故障。 在松质骨中，内部结构由支柱（小梁）和板的三维网络组成，其中失效首先由单个小梁的屈曲和/或断裂触发。 本研究的最终目标是表征这些失效起始部位的物理特性，以确定研究中的两种材料中的每一种是否存在局部结构中的共同弱点。 此外，从一个或多个局部包含的区域到更全球规模的故障的进展在预测材料故障方面也是非常感兴趣的。