RII Track-4: NSF: Soft Architected Metamaterials for Extreme Energy Dissipation

设计创新的轻质材料和结构，在动态机械载荷下具有显著的能量耗散，对于在操作条件下保护资产和人员并使其有效发挥作用至关重要。由空间周期性微结构组成的软结构超材料（SAM）由于材料性质和几何形状之间的相互作用而表现出新的和/或定制的能量耗散行为。尽管有希望，仍然缺乏基本的了解变形机制和能量耗散途径的自组装，以及结构-性能的关系，可以利用设计新的结构安排，提高生存能力。在普渡大学（PU）的主要研究合作者Weinong Chen教授的支持下，该项目旨在使用计算和实验相结合的方法研究受到动态机械载荷的SAMs的变形和失效机制。通过该研究项目获得的基本见解将能够开发先进的建筑材料，并填补知识空白，以设计建筑超材料，以增强能量耗散。PI和合作者之间的合作不仅为两个机构之间的持续研究奠定了基础，而且还将加强PI研究小组的研究竞争力，并通过PI的协同劳动力培训，课程开发和推广活动使学生，路易斯维尔大学和肯塔基州受益。这个研究基础设施改善轨道-4 EPSCoR研究员项目提供了一个奖学金，以助理教授和培训的研究生在路易斯维尔大学肯塔基州。研究的总体目标是通过与PU的Weinong Chen教授的新合作，研究SAMs的低振幅弹性波传播和高速冲击能量耗散机制的主动和可重构控制。为了实现这一目标，PI将带来他在超材料设计和建模方面的专业知识。主要合作者将在高加载速率下提供新型动态材料表征技术的补充专业知识。PU独特的改良Kolsky压杆和高速同步加速器X射线相衬成像系统对于捕获SAM中的实时断裂过程至关重要，包括撞击事件期间的损伤引发和传播以及多种失效模式之间的相互作用。这些实验将与建模工作紧密结合，通过校准模型参数和验证模型来推进研究。具体的研究目标和方法是：（1）使用一套具有通过基于物理的本构材料模型建模的行为的构建块来构建高级建模环境，（2）分别开发用于应变工程弹性波传播和冲击能量耗散的高保真多物理场和多尺度计算模型，以及（3）使用3D扫描激光多普勒测振仪实验性地表征弹性波传播，并且使用高速同步加速器X射线成像系统实时地表征SAM原型的损伤。成功完成拟议的研究将大大推进我们对SAM动态力学行为的基本理解，并最终促进具有改进能量耗散能力的新型结构超材料的设计，这些超材料可以在恶劣的工作环境中使用。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

Designing innovative lightweight materials and structures with significant energy dissipation against dynamic mechanical loads is critical for protection and effective performance of assets and personnel in operational conditions. Soft architected metamaterials (SAMs) consisting of spatially periodic microstructures show new and/or customized energy dissipation behaviors due to the interplay between material properties and geometry. Despite the promise, there remains a lack of fundamental understanding of deformation mechanisms and energy dissipation pathways in SAMs, as well as the structure-property relationships that could be leveraged to devise novel structural arrangements for enhanced survivability. With support from the primary research collaborator Prof. Weinong Chen at Purdue University (PU), this project aims to investigate the deformation and failure mechanisms of SAMs subjected to dynamic mechanical loading using a combined computational and experimental approach. The fundamental insights gained through this research project will enable the development of advanced architected materials and fill the knowledge gap to engineer architected metamaterials for enhanced energy dissipation. The collaboration between the PI and the collaborator will not only lay a foundation for continued research between the two institutions but will also strengthen the research competitiveness of the PI’s research group and benefit students, University of Louisville, and the State of Kentucky through the PI’s synergistic workforce training, curriculum development, and outreach activities. This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project provides a fellowship to an Assistant Professor and training for a graduate student at the University of Louisville at Kentucky. The overarching goal of the research research is to investigate active and reconfigurable control of low amplitude elastic wave propagation and high-velocity impact energy dissipation mechanisms of SAMs through a new collaboration with Prof. Weinong Chen at PU. To achieve this goal, the PI will bring his expertise in metamaterial design and modeling. The primary collaborator will provide complementary expertise in novel dynamic material characterization techniques at high loading rates. The unique modified Kolsky compression bar and high-speed synchrotron X-ray phase contrast imaging system at PU is essential to capture the real-time fracture processes in SAMs, including damage initiation and propagation during impact events and the interaction between multiple failure modes. These experiments will be critically integrated with modeling work to advance the research by calibrating model parameters and validating models. The specific research objectives and methods are to (1) construct an advanced modeling environment using a suite of building blocks with behaviors modeled through a physics-based constitutive material model, (2) develop high-fidelity multiphysics and multiscale computational models for strain engineered elastic wave propagation and impact energy dissipation, respectively, and (3) experimentally characterize elastic wave propagation using a 3D scanning laser Doppler vibrometer and real-time damage of SAM prototypes using the high-speed synchrotron X-ray imaging system. Successful completion of the proposed research will significantly advance our fundamental understanding of the dynamic mechanical behavior of SAMs and will ultimately facilitate the design of novel architected metamaterials with improved energy dissipation capabilities that can serve in harsh operating environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.