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dc.contributor.authorSchwartz, Kyle Wayneen_US
dc.date.accessioned2014-03-14T20:44:07Z
dc.date.available2014-03-14T20:44:07Z
dc.date.issued2006-08-04en_US
dc.identifier.otheretd-08242006-180234en_US
dc.identifier.urihttp://hdl.handle.net/10919/34742
dc.description.abstractPneumatic percussion tools are extensively used in the construction industry. They are one of the noisiest machines in the construction industry generating noise levels above 110 dBA which are well beyond the permissible exposure limit (PEL) of 85 dBA. This work presents a comprehensive methodology for the acoustic characterization and noise source identification of these percussion tools. The methodology is applied to a representative pneumatic tool and the characterization results are described in detail. A mechanical analysis was performed on a chipping hammer finding mode shapes and natural frequencies of individual components. The mechanical analysis included modal hammer measurements and creating FE models. Fluid measurements were performed on the chipping hammer to find the velocity of the exhaust and pressure in the upper and lower chambers. The fluid tests found that the velocity of the exhaust is approximately Mach 1.0 or greater. Noise measurements were carried out on the chipping hammer to determine the spectral characteristics, overall sound power level, and spatial source strength maps of the tool. A spherical array of microphones was used to obtain an accurate estimate of the overall sound power levels and the directivity. The overall sound power radiation was found to be in the range of 110-115dBA. An advanced 63 microphone phased array was used to successfully locate and identify the major sources of noise from this tool via the use of beam-forming maps. This thesis also presents a preliminary noise control method employing commercial-off-the-shelf pneumatic silencers. The outcome of the tests is illustrated in detail in this thesis.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartKSchwartz_Thesis_v3.pdfen_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.subjectNoise Controlen_US
dc.subjectPneumatic Percussion Toolsen_US
dc.subjectAcoustic Characterizationen_US
dc.subjectChipping Hammeren_US
dc.subjectPhased Arrayen_US
dc.titleAcoustic Characterization and Preliminary Noise Control of Pneumatic Percussion Toolsen_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.committeechairBurdisso, Ricardo A.en_US
dc.contributor.committeememberInman, Daniel J.en_US
dc.contributor.committeememberJohnson, Martin E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08242006-180234/en_US
dc.date.sdate2006-08-24en_US
dc.date.rdate2006-10-12
dc.date.adate2006-10-12en_US


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