A Study of Durability for Elastomeric Fuel Cell Seals and an Examination of Confinement Effects in Elastomeric Joints

dc.contributor.authorKlein, Justinen
dc.contributor.committeechairDillard, David A.en
dc.contributor.committeememberMoore, Robert Bowenen
dc.contributor.committeememberCase, Scott W.en
dc.contributor.departmentEngineering Mechanicsen
dc.date.accessioned2014-03-14T20:36:31Zen
dc.date.adate2010-05-27en
dc.date.available2014-03-14T20:36:31Zen
dc.date.issued2010-05-04en
dc.date.rdate2013-04-17en
dc.date.sdate2010-05-12en
dc.description.abstractProton exchange membrane fuel cells typically consist of stacks of membrane electrode assemblies sandwiched between bipolar plates, effectively combining the individual cells in series to achieve the desired voltage levels. Elastomeric gaskets are commonly used between each cell to insure that the reactant gases are isolated; any failure of a fuel cell gasket can cause the reactants to mix, which may lead to failure of the fuel cell. An investigation of the durability of these fuel cell seals was performed by using accelerated characterization methods. A hydrocarbon sealant was tested in five different environments to simulate fuel cell conditions. Viscoelastic properties of these seals were analyzed using momentary and relaxation compressive stress tests. Material properties such as secant modulus at 100% strain, tensile strength, and strain at failure were determined using dog-bone samples aged at several different imposed strains and aging times in environments of interest. Tearing energy was evaluated using trouser test samples tested under different rates and temperatures after various environmental aging conditions. Additionally, tearing tests were conducted on samples tested in liquid environment. A viscoelastic and mechanical property characterization of these elastomeric seals under accelerated aging conditions could help understand the behavior and predict durability in the presence of mechanical and environmental loading. Additionally, the effects of confinement have been evaluated for a bonded joint with varying thickness along the bonded direction. The Dreaming project is a glass art project in Fredrick, MD which incorporates such a varying thickness joint where thermal expansion of the adhesive has caused the glass adherend to break and debonding of the sealant. To examine this joint design, finite element analysis has been used to determine the effects of thermal expansion on such a complex geometry. Nine different test geometries have been evaluated to determine the effect of confinement coupled with thermal expansion on joint design with an elastomeric adhesive. Once evaluated, design changes were performed to try to reduce the loading while maintaining the general joint design. Results of this analysis can be used to determine the effects of confinement on a complex elastomeric joint.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-05122010-173824en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05122010-173824/en
dc.identifier.urihttp://hdl.handle.net/10919/32666en
dc.publisherVirginia Techen
dc.relation.haspartKlein_JE_T_2010.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectDegradationen
dc.subjectDurabilityen
dc.subjectLifetimeen
dc.subjectStress Relaxationen
dc.subjectConfinementen
dc.subjectStrain Energy Release Rateen
dc.subjectThermal Expansionen
dc.subjectElastomeren
dc.subjectVarying Thicknessen
dc.titleA Study of Durability for Elastomeric Fuel Cell Seals and an Examination of Confinement Effects in Elastomeric Jointsen
dc.typeThesisen
thesis.degree.disciplineEngineering Mechanicsen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen
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