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Stress- and Temperature-Induced Phase Transforming Architected Materials with Multistable Elements

thesis
posted on 28.11.2019, 13:40 by Yunlan Zhang

Architected materials are a class of materials with novel properties that consist of numerous periodic unit cells. In past investigations, researchers have demonstrated how architected materials can achieve these novel properties by tailoring the features of the unit cells without changing the bulk materials. Here, a group of architected materials called Phase Transforming Cellular Materials (PXCMs) are investigated with the goal of mimicking the novel properties of shape-memory alloys. A general methodology is developed for creating 1D PXCMs that exhibit temperature-induced reverse phase transformations (i.e., shape memory effect) after undergoing large deformations. During this process, the PXCMs dissipate energy but remain elastic (i.e., superelasticity). Next, inspired by the hydration-induced shape recovery of feathers, a PXCM-spring system is developed that uses the superelasticity of PXCMs to achieve shape recovery. Following these successes, the use of PXCMs to resist simulated seismic demands is evaluated. To study how they behave in a dynamic environment and how well their response can be estimated in such an environment, a single degree of freedom-PXCM system is subjected to a series of simulated ground motions. Lastly, the concept of PXCMs is extended into two dimensions by creating PXCMs that achieve superelasticity in two or more directions. Overall, the findings of this investigation indicate that PXCMs: 1) can achieve shape memory and recovery effects through temperature changes, 2) offer a novel alternative to traditional building materials for resisting seismic demands, and 3) can be expanded into two dimensions while still exhibiting superelasticity.

Funding

National Science Foundation

Air Force Office of Scientific Research

History

Degree Type

Doctor of Philosophy

Department

Civil Engineering

Campus location

West Lafayette

Advisor/Supervisor/Committee Chair

Pablo Zavattieri

Additional Committee Member 2

Andres F. Arrieta Diaz

Additional Committee Member 3

Santiago Pujol

Additional Committee Member 4

Nilesh D. Mankame

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