Internal damping is considered to be an important materialrnproperty for the wood used in the construction of violins.rnHowever measurements on assembled violins return onlyrnthe total damping, which is the sum of the internal,rnradiative, and fixture damping contributions. By measuringrnacoustic radiation over a sphere from a violin suspendedrnin a support fixture with negligible damping, it is possiblernto compute the radiation efficiency, and hence thernradiation damping, for each normal mode. Radiationrndamping corrections return "true" values of internalrndamping as a function of mode frequency that are easilyrnfit with appropriate functional forms. As a bonus thernfraction of vibrational energy that is converted to acousticrnenergy for each mode can be computed from the radiation-rn/total- damping ratio. Internal damping results based onrnmodal and acoustic analysis of nine quality-rated violinsrnare examined as a possible way of differentiating betweenrn"good" and "bad" violins.
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