Acoustic Characterization and Preliminary Noise Control of Pneumatic Percussion Tools

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dc.contributor.authorSchwartz, Kyle Wayneen
dc.contributor.committeechairBurdisso, Ricardo A.en
dc.contributor.committeememberInman, Daniel J.en
dc.contributor.committeememberJohnson, Martin E.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T20:44:07Zen
dc.date.adate2006-10-12en
dc.date.available2014-03-14T20:44:07Zen
dc.date.issued2006-08-04en
dc.date.rdate2006-10-12en
dc.date.sdate2006-08-24en
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
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-08242006-180234en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08242006-180234/en
dc.identifier.urihttp://hdl.handle.net/10919/34742en
dc.publisherVirginia Techen
dc.relation.haspartKSchwartz_Thesis_v3.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectNoise Controlen
dc.subjectPneumatic Percussion Toolsen
dc.subjectAcoustic Characterizationen
dc.subjectChipping Hammeren
dc.subjectPhased Arrayen
dc.titleAcoustic Characterization and Preliminary Noise Control of Pneumatic Percussion Toolsen
dc.typeThesisen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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