ASA 125th Meeting Ottawa 1993 May

4pMU2. Dynamic mechanical properties of violin wood and the tone qualities of violins. II: Relation of dynamic mechanical properties to the plate tuning of violins.

Carleen M. Hutchins

Morton A. Hutchins

Catgut Acoust. Soc., 112 Essex Ave., Montclair, NJ 07042

Edwin R. Fitzgerald

Johns Hopkins Univ., Baltimore, MD 21218

Desirable mechanical properties of density, vibrational damping, Young's modulus, velocity of sound, and the ratio of velocity to density for spruce tops and maple backs of violins have been fairly well established [I. Barducci and G. Pasqualini, Nuovo Cimento 5 (5), 416--466 (1948); J. C. Schelleng, J. Acoust. Soc. Am. 35, 326--338 (1963); F. Rocaboy and V. Bucur, Catgut Acoust. Soc. J. 1 (6) (Ser. II), 21--28 (1990)]. However the longitudinal to cross grain ratios of Young's modulus and the shear modulus, as well as their relationships in both spruce and maple have not been studied extensively. This work is concerned with the extent to which these ratios can vary and still make possible the optimum plate tuning of modes #1, #2, and #5 in violin top and back free plates. From a 1975 shipment of commercially available German spruce and maple, ten sets of violin top and back flitches were built into 10 normal violins. The plate tunings of six sets of these will be charted and discussed in relation to their mechanical properties.