Mechanical Behavior and Crushing of Cellular Materials

固体泡沫具有较高的硬度和强度重量比、出色的能量吸收特性以及出色的绝缘和声学性能。因此，它们是夹层结构、各种车辆的减震和能量吸收应用中的理想材料，作为声音和热量的隔热材料，以及储能等。这些特性源于它们的蜂窝状微结构。该项目使用X射线层析成像来表征这种微结构。提取的几何图形被引入到微观机械精确的分析和有限元模型中，这些模型与基础材料的特性一起使用来计算对压缩载荷的机械响应。该项目的独特之处在于，它模拟了初始弹性性质、屈服开始、应力平台的水平和程度，并以致密化结束。这项新的工作将把微观结构的随机性引入到模型中，以及在多轴和动态加载下的行为。将对聚合物泡沫和金属开孔和闭孔泡沫进行分析。该项目旨在将科学带入一个迄今的经验课题。所开发的模型和闭合形式的性能表达式可用于设计泡沫塑料以适应应用。该项目将培训研究人员，使其成为学术界和工业界未来多学科研究的领导者。这些成果通过期刊出版物、会议和大学讲座以及与该领域的国际和工业研究人员的接触来传播。后者的作用是将结果直接传播给用户，并帮助保持项目的针对性。

Solid foams have high stiffness- and strength-to-weight ratios, excellent energy absorption characteristics and exceptional insulation and acoustic properties. They are thus ideal materials as cores in sandwich structures, in impact mitigation and energy absorption applications in vehicles of all kinds, as insulation materials for sound and heat, for energy storage, etc. These characteristics arise from their cellular microstructure. This project uses X-ray tomography to characterize such microstructures. The geometry extracted is introduced into micromechanically accurate analytical and finite element models that are used together with the properties of the base material to calculate the mechanical response to compressive loads. The uniqueness of the project is that it models the initial elastic properties, the onset of yielding, the level and extent of the stress plateau and ends with densification. The new work will introduce the randomness of the microstructure to the models as well as the behavior under multiaxial and dynamically applied loads. Both polymeric and metallic open- and closed-cell foams will be analyzed.The project aims to bring science to a hitherto empirical subject. The models and closed-form expressions of properties developed can be used to design foams to fit the application. The project will train researchers to become future leaders in multidisciplinary research in academia and industry. The results are disseminated through journal publications, conferences and university lectures and through contact with international and industrial researchers in the field. The latter serve to disseminate results directly to users and help keep the project pointed towards what is practical.