Acoustic analysis of wood cell structures

Abstract

The study of wood acoustics is relevant to both understanding the biological functions of living trees and designing renewable sound-absorbing materials. This understanding can be enhanced through micromechanical models that relate wood microstructure to its acoustic properties. This paper begins by introducing three-dimensional modeling for microscale wood structures, confirming the elastic properties of wood cell wall layers. The equation of motion, incorporating element stiffness, mass matrices, and the force vector of a single substructure, is analyzed to assemble the global dynamic stiffness matrix of a wood cell. Free wave propagation characteristics are then examined by solving eigenvalue problems within both direct and inverse wave finite element method frameworks. The dispersion relations of positive-going waves are illustrated for a wood cell without a pit. Additionally, the forced response and displacement field of a wood cell without a pit are explored. Finally, wave diffusion, including reflection and transmission coefficients, is examined in a wood cell with a pit. The results demonstrate the proposed approach’s potential for investigating wave propagation and diffusion characteristics in microscale wood structures.