Trunk asymmetry and spruce wood resonant properties variability with respect to the cardinal points and the tree height

Ilyich Fedyukov,Yurevich Chernov,Sergeyevna Chernova,Yurevna Saldaeva

doi:10.5937/jaes15-13159

Abstract

Decks of musical instruments are developed from sawn wood products of strictly radial cutting and, as a rule, for this purpose the wood is selected according to the radius of a trunk from a certain forest site. An important factor for manufacturing high-quality (custom-made) musical instruments is the account of position of the best zone of a tree trunk with respect to the cardinal points. Observance of this condition becomes complicated by the fact that frequently trunks have the form of an abnormal cylinder with a displaced and curved axis (asymmetry). Physical and mechanical properties of wood vary greatly along trunk height; it is sometimes difficult to define the part of trunk wood with the best acoustic parameters. The paper presents the following research results: external and internal asymmetry of spruce trunks; macrostructures and acoustic constants of wood on northern and southern sides of a trunk; changes of cross-section sound velocity in wood along tree height and depending on the trunk diameter; dependence of sound velocity in wood on biometric data of a trunk. Based on the results of the experiment done, the estimation of cardinal points and position of wood at trunk height influencing the parameters of its 'musicality' is made. The data obtained and conclusions of the research are of scientific interest and bear practical recommendations for correct selection of wood with unique acoustic properties from a spruce-tree trunk.

Highlights

No practical value is usually given to and change of wood properties depending on its facing the cardinal points is not taken into account with forest products of general and special purpose, including timber blanks and parts for manufacturing musical instruments for wide use
The asymmetry was studied on trunk collars of circular saw cuts 50 mm thick from 9 average spruce trees at trunk height of 1.3 m and at its different relative heights: 0.2 Н; 0.5 Н; 0.7 Н (Figure 1), where Н is the height of a tree
Vladimir Ilyich Fedyukov - Trunk asymmetry and spruce wood resonant properties variability with respect to the cardinal points and the tree height and the same diameter strictly; basically, Аint characterizes the bias of medullary sheath from the trunk center (Figure 2, b).To perform these measurements the diameter was selected where there was a maximal difference in size of radii R and r

Summary

INTRODUCTION

No practical value is usually given to and change of wood properties depending on its facing the cardinal points is not taken into account with forest products of general and special purpose, including timber blanks and parts for manufacturing musical instruments for wide use. The choice of the material given is caused by its wide application in the manufacture of many kinds of musical instruments This is connected with the fact that macrostructure parameters (width of annual rings and late wood contents) are included in national standards of many countries as the basic criterion for selecting resonant forest products. In the work under consideration, density was studied in interrelation with the dynamic modulus of elasticity and the sound velocity included in the formula for defining acoustic constant as the basic criterion of wood ‘musicality’ according to formulas for sound velocity and Young’s dynamic modulus in wood

MATERIALS AND METHODS

Asymmetry direction

Tree ring width or Anual ring width Late wood content

CONCLUSION