Mechanics of periodic elastomeric structures with varying void volume fraction and thin-film coating

Super-elastic periodic structures possess special mechanical, photonic, phononic, and topological properties, making them particularly relevant for application at the micro and nano length scales. This study examines the behavior of such materials in two and three dimensions when void volume fraction is varied and a thin-film coating is incorporated. Computer modeling was used to predict and understand the mechanics of the transformation behavior; results showed that three-dimensional specimens behaved like their 2D counterparts and that addition of the film influenced structural transformation. Specifically, increasing volume fraction brought pattern transformation at lower values of stress and strain. Conversely, film presence postponed transformation and made it a gradual process. The film also showed considerable out-of-plane displacement and created a channel which spanned the structure. Out-of-plane motion and pattern transformation were verified experimentally by loading a 90 x 110 mm specimen to a strain of about 13% using a testing fixture. Although conducted in the macroscopic domain, experimental behavior can be expected at smaller length scales. The transformations and the surface topology alterations are reversible upon unloading, giving the ability to use deformation as a means of tuning or switching wave propagation properties that depend on periodicity, and surface properties that depend on topology.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Kozlowski, Michael C. (Michael Charles)

Advisor dc:contributor.advisor

• Mary C. Boyce.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/45822

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/45822