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dc.contributor.advisorBaker, Steven R.
dc.contributor.authorHansberry, Robert J.
dc.dateDecember 1994
dc.date.accessioned2014-08-13T20:26:39Z
dc.date.available2014-08-13T20:26:39Z
dc.date.issued1994-12
dc.identifier.urihttp://hdl.handle.net/10945/42812
dc.description.abstractA Modal analysis of a PHALANX gun assembly was conducted in the laboratory at Naval Postgraduate School. The goal of this analysis is to provide a dynamical description of the gun for studies of the effects of gun modifications on bullet dispersion. Accelerometer data were collected from five locations on the topmost barrel of the barrel assembly while the gun was being excited at the barrel tips with a swept sine forcing signal. This was done for five configurations of the gun, four of which did not include the production muzzle restraint, and the fifth that did. Frequency response data (vertical displacement/vertical force) were processed using the STARModal modal analysis software to extract modal parameters (frequencies, damping, and mode shapes) for frequencies up to 500Hz. For the four unrestrained configurations, there were no major differences in frequency response spectra, modal frequencies, or modal shapes. Eight modes were identified below 500Hz. For some modes the shape of the barrel assembly motion was very similar, suggesting that other structural responses might be present. The fifth configuration, with muzzle restraint, was distinct from the others in all categories, generally displaying lower modal frequencies and a higher modal frequency density. Thirteen modes were identified below 500Hz for this configuration. Again, there was some repetition of barrel assembly shapes for different modes. This study shows that the addition of the muzzle restraint, which was designed to reduce barrel tip vibration has resulted in a much higher modal density for frequencies above about 125Hz. This is significant, since it is known that the frequency spectrum of the forcing function of a firing bullet has significant amplitude above 125Hz.en_US
dc.description.urihttp://archive.org/details/modalnalysisofph1094542812
dc.format.extent95 p.en_US
dc.language.isoen_US
dc.publisherMonterey, California. Naval Postgraduate Schoolen_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, it may not be copyrighted.en_US
dc.titleModal analysis of the PHALANX M61A1 close-in weapons systemen_US
dc.typeThesisen_US
dc.contributor.corporateNaval Postgraduate School (U.S.)
dc.subject.authorNAen_US
dc.description.serviceU.S. Marine Corps (USMC) authoren_US
dc.identifier.oclcocn640627917
etd.thesisdegree.nameM.S. in Applied Physicsen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineApplied Physicsen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US


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