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.
