Finite Element Modeling and Exploration of Double Hearing Protection Systems

dc.contributor.authorJames, Christian Monjeen
dc.contributor.committeechairWest, Robert L. Jr.en
dc.contributor.committeememberSaunders, William R.en
dc.contributor.committeememberHomma, Kenjien
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T20:32:04Zen
dc.date.adate2006-03-10en
dc.date.available2014-03-14T20:32:04Zen
dc.date.issued2006-02-10en
dc.date.rdate2006-03-10en
dc.date.sdate2006-02-22en
dc.description.abstractNoise levels in modern industrial and military environments are constantly increasing, requiring the improvement of current hearing protection devices. The improvement of passive hearing protection devices lies in examining the performance of major contributors to reduction of noise attenuation. The finite element method can be used to fully explore single hearing protection (SHP) and double hearing protection (DHP) systems, and the major performance mechanisms can be observed numerically as well as visually in modern postprocessing software. This thesis focuses on developing and evaluating double hearing protection finite element models, and exploring the behavior mechanisms responsible for reduced noise attenuation. The double hearing protection model studied consists of an earmuff preloaded to a barrier covered to simulate human flesh, and a foam earplug installed inside a rigid cylinder designed to simulate the human ear canal. Pressure readings are taken at the bottom of the simulated ear canal assembly. Advanced finite element models are used to reconcile differences between the experimental and finite element results, and to investigate the behavior of the modeled system. The foam earplug material properties for the finite element model are required in the same shear state of stress and boundary condition configuration as the experimental DHP setup, therefore a novel material extraction method is used to obtain this data. The effects of radial compression preload on the earplugs are considered, and the resulting foam earplug shear material properties are input into the finite element DHP model where the effects of the updated foam material properties are observed.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-02222006-134938en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-02222006-134938/en
dc.identifier.urihttp://hdl.handle.net/10919/31310en
dc.publisherVirginia Techen
dc.relation.haspartChristian_M_James_Thesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectFinite element analysisen
dc.subjectviscoelasticen
dc.subjectearplugen
dc.subjectdouble hearing protectionen
dc.titleFinite Element Modeling and Exploration of Double Hearing Protection Systemsen
dc.typeThesisen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Christian_M_James_Thesis.pdf
Size:
1.8 MB
Format:
Adobe Portable Document Format

Collections