Mechanical Behavior and Crushing of Cellular Materials

固体泡沫具有高刚度和强度重量比、优异的能量吸收特性以及卓越的绝缘和声学性能。因此，它们是理想的材料，作为夹层结构的核心，在各种车辆中的冲击缓解和能量吸收应用，作为隔音隔热材料，用于能量存储等。该项目使用X射线层析成像来表征这种微结构。提取的几何形状被引入到微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，以计算对压缩载荷的机械响应。该项目的独特之处在于，它模拟了初始弹性特性、屈服开始、应力平台的水平和范围，并以致密化结束。新的工作将介绍随机性的微观结构的模型，以及在多轴和动态施加的负载下的行为。将分析聚合物和金属开孔和闭孔泡沫。该项目旨在将科学引入迄今为止的经验主题。所开发的模型和封闭形式的性能表达式可用于设计泡沫，以适应应用。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。研究结果通过期刊出版物、会议和大学讲座以及通过与该领域的国际和工业研究人员的联系传播。后者的作用是将结果直接传播给用户，并帮助项目保持实用性。

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.