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的有效性能至关重要。由空间周期性微结构组成的软结构超材料（sam）由于材料特性和几何结构之间的相互作用而表现出新的和/或定制的能量耗散行为。尽管前景很好，但对地对空导弹的变形机制和能量耗散途径，以及可以用来设计提高生存能力的新型结构安排的结构-性能关系，仍然缺乏基本的理解。在主要研究合作者普渡大学（PU）的陈伟农教授的支持下，该项目旨在采用计算和实验相结合的方法研究sam在动态机械载荷下的变形和破坏机制。通过该研究项目获得的基本见解将使先进建筑材料的发展成为可能，并填补了设计建筑超材料以增强能量耗散的知识空白。PI与合作者之间的合作不仅将为两所机构之间的持续研究奠定基础，而且将加强PI研究小组的研究竞争力，并通过PI的协同劳动力培训，课程开发和外展活动使学生，路易斯维尔大学和肯塔基州受益。该研究基础设施改善轨道4 EPSCoR研究人员项目为肯塔基州路易斯维尔大学的助理教授和研究生提供奖学金。研究的总体目标是通过与PU的陈伟农教授的新合作，研究地对空导弹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。主要合作伙伴将在高加载率下提供新的动态材料表征技术方面的补充专业知识。PU独特的改良Kolsky压缩杆和高速同步加速器x射线相衬成像系统对于捕获sam的实时断裂过程至关重要，包括冲击事件中损伤的产生和扩展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)使用一套构建模块构建先进的建模环境，通过基于物理的本构材料模型建模行为；(2)分别为应变工程弹性波传播和冲击能量耗散建立高保真的多物理场和多尺度计算模型。(3)利用三维扫描激光多普勒测振仪实验表征弹性波的传播特性，并利用高速同步x射线成像系统对SAM原型机进行实时损伤表征。这项研究的成功完成将极大地促进我们对地空导弹动态力学行为的基本理解，并最终促进新型建筑超材料的设计，这些材料具有改进的能量耗散能力，可以在恶劣的操作环境中使用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.