Abstract:

Maple wood for back plates of bowed string instruments is more and more rare. The measuring of its properties is then, very topical. This paper is concerned with physicoacoustical characteristics such as density, Young's modulus of elasticity, and the acoustic constant, and their distribution along the radial direction in the trunk of a tree. The study was performed with the nondestructive Chladni method on plates. A bending beam vibrational mode along the grain was visualized and the pictures indicate interesting shapes caused by the heterogeneity of the wood and internal stress. Then, the plates were cut to sticks and the same mode was visualized. Also here, the distortion of nodal lines, when compared with homogeneous material, has been shown. The elastic characteristics were calculated from the natural frequencies of the modes. Such testing has been proven as useful for the quality determination of maple wood as a material for musical instrument making. [Work supported by Slovak Grant Scientific Agency.]