ToneRite ?

Examining the rheology of the system represented by the violin, a fatigue phenomenon is observed under a superimposition of two regimes: one dynamic, when the instrument vibrates during play, and another static, induced by the stress of the strings. To simulate in simplified manner the changes induced in a violin by playing it, specimens or violins loaded for a long
period of time can be used.

The scientific literature is very scarce on data concerning the influence of long-term mechanical loading on acoustical properties of resonance wood or those of on solid wood in general. Manasevici (1962) reported data on the effect due to 51 days of continuous flexural resonance vibration on the behavior of common pine wood specimens (20×50×1,000 mm). The amplitude of vibration was recorded. The maximum value of the amplitude was recorded at the 15th day of the experiment. During the following days, the amplitude decreased from the maximum value to a value higher than the initial value measured at the beginning of the experiments. Unfortunately the author did not report data on the resonance frequency or on the quality factor for the assessment of the modifications induced in the specimens.

Sobue and Okayasu (1992) studied the effect of continuous small amplitude vibrations on Young’s modulus and internal friction (tan 􀁇) in different species (softwoods and hardwoods). The free−free flexural vibration with small amplitude (from 0.015−0.40 mm) and frequency (100−170 Hz) was applied for 5 h. Young's modulus EL was not affected by the vibrational regime; rather the internal friction parameter tan 􀁇L decreased from 5 to 15%.