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dc.contributor.authorFox, Christopher Jamesen_US
dc.date.accessioned2014-03-14T20:32:07Z
dc.date.available2014-03-14T20:32:07Z
dc.date.issued2009-02-09en_US
dc.identifier.otheretd-02232009-141249en_US
dc.identifier.urihttp://hdl.handle.net/10919/31327
dc.description.abstractElectrical shorting through the proton exchange membrane (PEM) is a form of early failure commonly found in PEM fuel cells. In order to improve the durability and thus the commercial potential for PEM fuel cells, this form of failure must be understood and mitigated. This research investigates whether complete penetration is the most likely cause of shorting and establishes general parameters (force, contact pressure, temperature, and time) that lead to shorting in a typical PEM material, Nafion® NRE211. Data was obtained from a novel indentation apparatus that was coupled with an electrical circuit to assess the force and depth of penetration at which shorting occurs in a PEM at temperatures ranging from 70ï °C to 100ï °C. The results show that shorting occurs when full penetration is reached, based on both displacement at shorting, and resistance of the electrical circuit at shorting. In addition, a finite element model was created in a commercial finite element tool (Abaqus) in an attempt to predict time to penetration under loads and geometric configurations typically found in PEM fuel cells. The finite element model was investigated for use with standard Abaqus material modules (e.g. two-layer viscoplastic and hyperelastic-viscoelastic) describing Nafion® behavior. The results suggest that the standard material models do not sufficiently describe Nafion® behavior in this particular application and suggest the need for alternative material models that capture both the viscous and plastic nature of Nafion®.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartFoxThesis_ver7.pdfen_US
dc.relation.haspartCopyright_Permission_Table_3-2.docen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectfuel cellen_US
dc.subjectshortingen_US
dc.subjectNafion®en_US
dc.subjectmembraneen_US
dc.subjectAbaqusen_US
dc.subjectpenetrationen_US
dc.subjectPEMen_US
dc.subjectPEMFCen_US
dc.titleInvestigation of Shorting by Penetration in Pem Fuel Cell Membranesen_US
dc.typeThesisen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeechairEllis, Michael W.en_US
dc.contributor.committeememberCase, Scott W.en_US
dc.contributor.committeememberNelson, Douglas J.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-02232009-141249/en_US
dc.date.sdate2009-02-23en_US
dc.date.rdate2009-06-02
dc.date.adate2009-06-02en_US


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