- Title Information
- Title
- A Mechanics Study on Surface Ruga Morphologies of Soft Materials
- Name:
Personal
- Name Part
- Zhao, Ruike
- Role
- Role Term:
Text
- creator
- Origin Information
- Copyright Date
- 2016
- Physical Description
- Extent
- xix, 138 p.
- digitalOrigin
- born digital
- Note
- Thesis (Ph.D. -- Brown University (2016)
- Name:
Personal
- Name Part
- Kim, Kyung-suk
- Role
- Role Term:
Text
- Director
- Name:
Personal
- Name Part
- Gao, Huajian
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Franck, Christian
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. ENGINEERING: Mechanics of Solids
- Role
- Role Term:
Text
- sponsor
- Genre (aat)
- theses
- Abstract
- The surface morphologies of different soft material systems comprise various ruga phases (wrinkle, crease, fold or ridge). In the past a few decades, despite that one-phase specific studies have revealed certain intrinsic properties of some ruga phases, their evolutions and transitions between each other are still unclear. In this thesis, finite element analysis (FEA) is used to study soft-material surface deformation of a homogeneous half space, and one or multilayer thin film(s) on a substrate, every component of which is represented by an incompressible neo-Hookean solid. Furthermore, experiments are carried out by a self-tightening loading device to verify the distinct morphologies. Based on the simulation results, we construct the primary bilayer (PB) ruga-phase diagram which guides manipulation of various ruga configurations in bilayer systems. On the PB ruga-phase diagram, various phase boundaries represent bifurcation sites of ruga structures caused by lateral compression of the bilayer. All the ruga phases eventually evolve to a limit phase of either global crease or global fold localization, depending on the stiffness ratio of the bilayer, when compressed up to the Biot critical strain of 0.456. Moreover, the substrate pre-stretch promotes ridging of bilayers and ruga mode-period multiplications during loading. The ridging is intrinsically growth limited and highly dependent on both substrate pre-stretch and modulus ratio of the PB system. Configuration-mobility bifurcation of ridges, caused by symmetry breaking of individual ridge configuration, leads to order-disorder transition in the system. We pointed out two irreversibility types for a bilayer system with a stiff film. Irreversibility is typically exhibited through either mode locking or primary period switching. The former leads to cyclic hysteresis of ruga configurations during a loading/unloading cycle of the PB system without strain mismatch. The latter exhibits snap jumps in the PB ruga-phase transitions, enhanced by substrate pre-stretch and sufficient viscoelastic loss tangent. With multi-layered or graded modulus structure, ridging can be suppressed, and hierarchal wrinkle wavelengths can be observed during loading. Along this line, we summarize the ruga morphology control aspects and corresponding controlling factors.
- Subject
- Topic
- ruga-phase diagram
- Subject
- Topic
- global localization
- Subject
- Topic
- strain mismatch
- Subject
- Topic
- irreversibility
- Subject
- Topic
- mobility bifurcation
- Subject
- Topic
- order-disorder transition
- Subject
- Topic
- morphology control
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20160629
- Language
- Language Term:
Code (ISO639-2B)
- eng
- Language Term:
Text
- English
- Identifier:
DOI
- 10.7301/Z0416VF3
- Access Condition:
rights statement
(href="http://rightsstatements.org/vocab/InC/1.0/")
- In Copyright
- Access Condition:
restriction on access
- Collection is open for research.
- Type of Resource (primo)
- dissertations