Integration of imaging and mechanics for advanced material characterization and structural repair

材料研究是一系列看似不同的应用领域进展的核心，涉及结构、路面、汽车和新兴生物医学技术。例如，加拿大老化的基础设施正在恶化，需要立即修复或更新，这给我们的经济带来了巨大的压力，并突显了对新方法的迫切需求，以评估和推迟结构材料的失效。所提出的研究方案将混凝土材料的表征从传统的整体‘评价’推进到基于组分的表征。将研究孔洞含量、裂纹扩展、腐蚀细观力学和修复方案对材料性能的影响。这种创新的方法将提供详细的基于图像的应力分布和变形图，以识别故障的起始和传播。随着项目的发展，潜在的新研究方向的范围可以扩大到包括断裂力学、钢焊接、沥青和生物材料。*拟议研究的主要目标是开发一种融合成像、计算力学和实验的混凝土力学表征的新方法。将通过成像监测裂缝和夹杂物的三维(3D)形态、空间分布和扩展，如空洞和腐蚀产物。计算骨料、钢筋和纤维增强聚合物(FRP)片材的应力和应变。这些研究将为优化材料混合设计和修复方案铺平道路，并将全面了解每个组件的强度、形态和表面纹理对材料性能的作用。*将实施实验测试、3D成像和特定样本的有限元(FE)建模。将使用计算机断层成像系统获取微尺度图像，以识别骨料、腐蚀产物、空洞和裂缝的空间和几何形状。图像将被传输到详细的3D和基于组件的有限元模型，以调查应力集中的强度和位置。每个组件都将使用其自己的机械属性、空间分布和几何形状进行建模。此外，每个元素与其他组件的相互作用将使用界面力学进行建模，以研究脱粘行为。*拟议的研究将在成像、力学和新兴的图像-力学集成技术方面提供独特的培训机会，为毕业生在努力寻找创新解决方案的多个领域工作做准备，包括无损检测、制造、结构工程和生物物理学。这项创新研究将对延长加拿大和世界现有和更新基础设施的使用寿命和提高承载能力产生直接影响，同时通过有效利用材料来降低维修和更新成本。

Materials research is at the heart of advances in a broad range of seemingly disparate applications, spanning structures, pavement, automotive and emerging biomedical technologies. For example, Canada's aging infrastructure is deteriorating at a rate that requires immediate repair or renewal, placing a huge strain on our economy and highlighting a critical need for new methods to evaluate and delay structural materials failure. The proposed research program advances concrete material characterization from the conventional overall' evaluation to a components-based' characterization. The role of void contents, cracks propagation, corrosion micromechanics and repair schemes on material performance will be investigated. This innovative approach will provide detailed image-based stress distribution and deformation maps to identify failure initiation and propagation. As the program grows, the scope of potential new research directions can expand to include fracture mechanics, steel welding, asphalt and biomaterials.******The main objective of the proposed research is to develop a novel approach for mechanical characterization of concrete that merges imaging, computational mechanics, and experiments. The three dimensional (3D) configuration, spatial distribution and propagation of cracks and inclusions, such as voids and corrosion products, will be monitored by imaging. Stress and strain of aggregate, reinforcement and fiber reinforced polymer (FRP) sheet will be calculated. Such investigations will pave the way for optimized material mix design and repair schemes, and will provide comprehensive understanding of the role of each component's strength, morphology, and surface texture on material behaviour. ***Experimental testing, 3D imaging and sample-specific finite element (FE) modeling will be implemented. Microscale images will be acquired using a computed tomography imaging system to identify spatial and geometric configurations of aggregate, corrosion product, voids and cracks. The images will be transferred to detailed 3D and components-based FE models to investigate intensity and locations of stress concentration. Each of the components will be modeled using its own mechanical properties, spatial distribution and geometry. In addition, each element's interaction with other components will be modeled using interfacial mechanics to investigate debonding behaviour. ******The proposed research will provide unique training opportunities in imaging, mechanics, and emerging techniques of image-mechanics integration that prepare graduates to work in a number of fields that strive to find innovative solutions, including non-destructive testing, manufacturing, structural engineering, and biophysics. This innovative research will have a direct impact on extending the service life and increasing the load carrying capacity of existing and renewed infrastructures in Canada and the world, while reducing the cost of repair and renewal by efficient use of materials.*****