Buckling patterns on pre-stretched bilayer shells
Name
1022267832-MIT.pdf
Description
Full printable version
Size
8.5 MB
Format
Adobe PDF
Checksum (MD5)
50a1a5f6ae863eccbd6faf3a8383ed69
Author(s)
Al-Rashed, Rashed Abdulazeez
Advisor(s)
Pedro M. Reis.
Date Issued
2017
Publisher
Massachusetts Institute of Technology
Abstract
We introduce a new experimental system to study the effects of pre-stretch on the buckling patterns that emerge from the biaxial compression of elastomeric bilayer shells. After fabricating our samples, releasing the pre-stretch in the substrate by deflation places the outer film in a state of biaxial compression and yields a variety of buckling patterns. We systematically explore the parameter space by varying the pre-stretch of the substrate and the ratio of film stiffness to substrate stiffness. The phase diagram of the system exhibits a variety of buckling patterns: from the classic periodic wrinkle to creases, folds, and high aspect ratio ridges. Our system is capable of easily transitioning between these buckling patterns, a first for biaxial systems. We focus on the wrinkle to ridge transition, where we find that pre-stretch plays an essential role in ridge formation, and that the ridge geometry (width, height) remains approximately constant throughout the process. For the localized ridge patterns, we find that the propagation of the ridge tip depends strongly on both strain and stiffness ratio, in a way that is akin to hierarchical fracture of brittle coatings.
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 59-63).
Subjects
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
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