GOALI: Phase Transforming Cellular Materials

随着我们对微结构材料力学认识的快速增长，以及在一定长度范围内制造这类材料的能力的相应提高，导致了具有独特性能组合的新一代材料，而传统材料很难获得这些性能组合。这个GOALI学术联络机会(GOALI)研究项目将探索蜂窝材料中相变的新概念，该概念可能会影响关键行业和应用领域，从具有集成能量吸收、能量收集和波传输能力的结构到自适应催化剂衬底和具有可切换润湿性和致动特性的材料。在基础材料研究阶段与汽车制造商密切合作，确保工作与行业需求保持相关性。本科生和研究生的教育和培训将是该项目不可分割的一部分，由于该项目的跨学科性质，参与该项目的学生将接触到这些材料的分析、合成和测试的不同方面。从这项研究计划中学到的信息将在国际会议上传播，在期刊出版物中传播，并直接带入课堂。此外，PI将与普渡大学的少数民族工程计划(MEP)合作，为当地博物馆开发社区外展活动。这项研究的目标是促进对一组新的相变细胞材料(PXCM)的理解，这些材料的构建块在受到适当的刺激时可以经历巨大的双或亚稳定构象变化，从而驱动相变。由于这种相变，多孔材料的有效性质在其稳定相之间是不同的。此外，相变过程本身导致了显著的能量耗散，而不会在基材中引起永久的非弹性变形。这两个方面都使人想起热力学系统中的一级相变。本研究计划将(A)研究PXCM在准静态加载和动态加载下的正向和反向应力诱导相变的动力学，(C)研究PXCM中正向和反向温度诱导相变的动力学，(D)系统地探索PXCM的设计空间，以及(E)采用解析和数值模拟与多尺度实验相结合的方法研究相变引起的波传播特性的变化。将特别强调将可逆的固态能量耗散能力整合到结构构件中。

Rapid growth in our understanding of the mechanics of micro-architectured materials complemented by a corresponding increase in the ability to manufacture such materials over a range of length scales has led to a new generation of materials with unique combinations of properties that are otherwise difficult to obtain with traditional materials. This Grant Opportunity for Academic Liaison with Industry (GOALI) research project will explore a new concept of phase transformation in cellular materials that could impact key industries and application areas ranging from structures with integrated energy absorption, energy harvesting and wave beaming capabilities to adaptive catalyst substrates and materials with switchable wettability and actuation properties. A close collaboration with an automotive manufacturer at the fundamental materials research stage ensures that the work remains relevant to industry needs. Education and training for undergraduate and graduate students will be an integral part of this project, and due to the interdisciplinary nature of the project, students involved in it will be exposed to diverse aspects of the analysis, synthesis and testing of these materials. Information learned from this research program will be disseminated at international conferences, in journal publications and brought directly into the classroom. Additionally, the PI will work with the Minority Engineering Program (MEP) at Purdue University to develop community outreach activities for local museums.The goal of this research is to advance the understanding of a novel set of phase transforming cellular materials (PXCMs) whose building blocks can undergo large bi- or meta-stable conformational changes when exposed to an appropriate stimulus that drives the phase transformation. As a result of this phase transformation, the effective properties of the cellular material are different between its stable phases. Moreover, the phase transformation process itself results in significant dissipation of energy without inducing permanent inelastic deformation in the base material. Both of these aspects are reminiscent of first-order phase transformations in thermodynamic systems. This research program will (a) study the kinetics of the forward and reverse stress-induced phase transformations in PXCMs under quasi-static loading, (b) and under dynamic loading, (c) study the kinetics of the forward and reverse temperature-induced phase transformations in PXCMs, (d) carry out a systematic exploration of the design space for PXCMs and (e) study the changes in wave propagation properties accompanying phase transformations using an approach that combines analytical and numerical modeling with experiments at multiple length scales. Special emphasis will be placed on the integration of reversible, solid-state energy dissipation capability into structural members.