Mechanical Behavior and Crushing of Cellular Materials

固体泡沫具有很高的刚度和强度重量比，优异的能量吸收特性以及优异的绝缘和声学性能。因此，它们是理想的材料，可作为夹层结构的核心材料，可用于各种车辆的冲击缓解和能量吸收应用，可作为隔音和隔热材料，可用于储能等。这些特征来自于它们的细胞微观结构。该项目使用x射线断层扫描来表征这种微观结构。将提取的几何形状引入到微力学精确的解析和有限元模型中，这些模型与基材的特性一起用于计算压缩载荷下的力学响应。该项目的独特之处在于，它模拟了初始弹性特性、屈服的开始、应力平台的水平和范围，并以致密化结束。新的工作将引入模型的微观结构的随机性，以及在多轴和动态载荷作用下的行为。将分析聚合物和金属开孔和闭孔泡沫。这个项目的目的是把科学带到一个迄今为止经验主义的课题上来。所建立的性能模型和封闭形式表达式可用于设计适合应用的泡沫材料。该项目将培养研究人员成为未来学术界和工业界多学科研究的领导者。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接触传播。后者的作用是将结果直接传播给用户，并帮助保持项目指向实际的方向。

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.