Role of damage in the failure of heterogeneous materials

损伤在异质材料失效中的作用

• 批准号: RGPIN-2018-06627
• 负责人: Pilkey, Keith
• 金额: $ 2.04万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=662191
• 关键词: Role; damage; failure; heterogeneous; materials

The proposed research program will use a state-of-the-art micro-computed tomography (microCT) facility at Queen's University, equipped with an in-chamber loading stage, to acquire 3D images of internal damage that develops as heterogeneous materials are progressively loaded to failure. Two very different classes of heterogeneous materials will be considered: steel and aluminum alloy sheet materials containing hard second-phase particles that nucleate small voids when subject to applied plastic strains, and cancellous bone tissue (i.e. the porous tissue in the ends of long bones and in vertebrae) that accumulates microcracks as a result of everyday mechanical cyclic loading. While these two materials are very different, a common investigative approach will be employed to study the role of damage in causing catastrophic failure.******The research to be undertaken is fundamental in nature, focusing on key local features that govern the onset of global catastrophic material failure. However, the knowledge to be gained by this research is of use to a number of receptors. The grades of steel and aluminum alloy sheet materials to be studied are used in a number of structural applications, such as car frames and body panels in the automotive industry, where premature material failure during part manufacturing or while in service is an ongoing issue. Hence the results are of potential interest to both material fabricators and part manufacturers. For the bone research, the relationship between the structure of cancellous bone, the presence of microcracks, and the resulting fracture strength is very complex. A better understanding of this relationship would not only advance our knowledge of this poorly understood failure behaviour, but it would also lead to improvements for biomechanical technologies, such as synthetic bone scaffolds and diagnostic imaging devices.******The major outcomes and impact of this research will be a better understanding of the role of damage in the failure of metal alloys and cancellous bone, with improved or new models to predict this behaviour. Highly-qualified personnel who work on this research will gain valuable skills in areas of image processing, computer coding, materials characterization (optical and scanning electron microscopy), design of mechanical fixtures and testing protocols, advanced data analysis (e.g. statistics), finite element method modelling, project management, problem solving, critical thinking, and oral presentation and technical writing skills.******The study of damage in the failure of cancellous bone represents a non-traditional topic in materials science and engineering that is likely to be more attractive to women and persons from under-represented groups in this field, as well as other related disciplines, e.g. mechanical engineering.**

拟议的研究计划将使用皇后大学最先进的微型计算机断层扫描（microCT）设施，配备室内加载阶段，以获取内部损伤的3D图像，这些损伤随着异质材料逐渐加载而发生故障。 将考虑两类非常不同的异质材料：含有硬第二相颗粒的钢和铝合金板材，当受到施加的塑性应变时，这些颗粒会形成小空隙;以及松质骨组织（即长骨末端和椎骨中的多孔组织），由于日常机械循环载荷，这些组织会积累微裂纹。 虽然这两种材料有很大的不同，但将采用一种共同的调查方法来研究损坏在造成灾难性故障中的作用。要进行的研究是根本性的，重点是控制全球灾难性材料失效的关键局部特征。 然而，这项研究所获得的知识对许多受体都有用。 要研究的钢和铝合金板材的等级用于许多结构应用中，例如汽车工业中的汽车框架和车身面板，其中在零件制造期间或在服务期间的过早材料失效是一个持续的问题。 因此，这些结果对材料制造商和零件制造商都具有潜在的意义。 对于骨研究而言，松质骨的结构、微裂纹的存在以及由此产生的断裂强度之间的关系是非常复杂的。 更好地理解这种关系不仅会提高我们对这种知之甚少的失效行为的认识，而且还会导致生物力学技术的改进，例如合成骨支架和诊断成像设备。这项研究的主要成果和影响将是更好地了解金属合金和松质骨失效中损伤的作用，并改进或建立新的模型来预测这种行为。从事这项研究的高素质人员将获得图像处理，计算机编码，材料表征（光学和扫描电子显微镜），机械夹具和测试协议设计，高级数据分析（例如统计学），有限元方法建模，项目管理，解决问题，批判性思维以及口头陈述和技术写作技能等领域的宝贵技能。松质骨破坏中的损伤研究代表了材料科学和工程中的一个非传统主题，可能对该领域以及其他相关学科（例如机械工程）中的女性和代表性不足的群体更具吸引力。