Thermally tunable band gaps in architected metamaterial structures

Nimmagadda, Chaitanya

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https://hdl.handle.net/2142/101826 Copy

Description

Title

Thermally tunable band gaps in architected metamaterial structures

Author(s)

Nimmagadda, Chaitanya

Issue Date

2018-07-17

Director of Research (if dissertation) or Advisor (if thesis)

Matlack, Kathryn H

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Phononic crystals
• metamaterials
• tunable band gaps
• architected materials
• vibration mitigation

Abstract

The combined characteristics of periodicity and locally resonant features in metamaterial structures, or meta-structures, give rise to unique wave propagation characteristics such as relatively low and wide band gaps. These meta-structures have a fixed geometry and thus a fixed behavior, however applications that require structural vibration mitigation such as spacecraft and automotive components have variable vibration mitigation requirements over a range of operation and external conditions. In this work, we propose a method to thermally tune the band gaps of composite meta-structures, which combine a periodic lattice and locally-resonant inclusions, through changes in temperature of the structure. The concept primarily takes advantage of the different moduli of the two materials in the meta-structure that have drastically different temperature dependences, to preferentially tune the modulus of the lattice material compared to the resonant inclusion. We introduce an additional concept, termed thermal partitioning, to partially or fully open and close band gaps by locally controlling the temperature within the meta-structure. We demonstrate these results numerically with finite element simulations.

Graduation Semester

2018-08

Type of Resource

text

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http://hdl.handle.net/2142/101826

Copyright and License Information

Copyright 2018 Chaitanya Nimmagadda

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