Mechanical Behavior and Quasi-Static and Dynamic Crushing of Cellular Materials

该项目的目标是将固体泡沫的蜂窝状微观结构与其超高的刚度重量比和强度重量比以及准静态和动态载荷下的优异能量吸收特性联系起来。本计画利用X线断层摄影术来表征金属泡沫与松质骨的随机胞状微结构。提取的几何形状和基础材料的机械性能被引入到微机械精确的分析和有限元模型，用于计算准静态和动态压缩下的机械响应;这从初始小变形线性弹性制度的大变形压碎制度。这项工作的独特之处在于对实际随机微观结构的分析，这些微观结构可能包括分级的细胞尺寸。 尽管我们在理解泡沫的微孔结构和力学性能之间的联系方面取得了重大进展，但该主题仍然是经验性的。该项目中开发的模型和封闭形式的属性表达式可用于设计泡沫以适应应用或评估患者骨骼的降解程度，从而将科学带入迄今为止的经验主题。该项目将培训研究人员成为学术界和工业界多学科研究的未来领导者。研究结果将通过期刊出版物、会议、大学讲座以及与该领域的国际和工业研究人员的联系进行传播。与工业研究人员的互动也有助于将结果直接传播给用户，并有助于保持项目指向实用的方向。

The goal of this project is to connect the cellular microstructure of solid foams to their superb high stiffness-to-weight and strength-to-weight ratios as well as excellent energy absorption characteristics under quasi-static and dynamic loadings. This project uses X-ray tomography to characterize the random cellular microstructure of metallic foams and trabecular bone. The geometry extracted and the mechanical properties of the base material are introduced into micromechanically accurate analytical and finite element models that are used to calculate the mechanical response under quasi-static and dynamic compression; this starts from the initial small deformation linearly elastic regime to the large deformation crushed regime. The uniqueness of the work lies in the analysis of actual random microstructures that may include graded cell sizes. Despite significant gains in our understanding of the connection between the cellular microstructure and the mechanical properties of foams, the subject remains empirical. The models and closed-form expressions of properties developed in this project can be used to design foams to fit the application or to evaluate the degree of degradation of patient bones, thus bringing science to the hitherto empirical subject. The project will train researchers to become future leaders in multidisciplinary research in academia and industry. The results will be disseminated through journal publications, conferences, university lectures, and through contact with international and industrial researchers in the field. Interaction with industrial researchers also serves to disseminate results directly to users and helps keep the project pointed towards a practical direction.