Wood Science and Technology

, Volume 47, Issue 2, pp 329–341

Determining moisture-dependent elastic characteristics of beech wood by means of ultrasonic waves

  • Tomasz Ozyhar
  • Stefan Hering
  • Sergio J. Sanabria
  • Peter Niemz
Original

DOI: 10.1007/s00226-012-0499-2

Cite this article as:
Ozyhar, T., Hering, S., Sanabria, S.J. et al. Wood Sci Technol (2013) 47: 329. doi:10.1007/s00226-012-0499-2

Abstract

The present study investigates the influence of moisture content on the elastic characteristics of beech wood (Fagus sylvatica L.) by means of ultrasonic waves. A set of elastic engineering parameters (i.e. three Young’s moduli, three shear moduli and six Poisson’s ratios) is determined at four specific moisture contents. The results reveal the significant influence of the moisture content on the elastic behaviour of beech wood. With the exception of some Poisson’s ratios, the engineering parameters decrease with increasing moisture content, indicating a decline in stiffness at higher moisture contents. At the same time, wood anisotropy, displayed by the two-dimensional representation of the velocity surface, remains almost unchanged. The results prove that the ultrasonic technique is suitable for determining the elastic moduli. However, non-diagonal terms of the stiffness matrix must be considered when calculating the Young’s moduli. This is shown experimentally by comparing the ultrasonic Young’s moduli calculated without, and allowing for, the non-diagonal terms. While the ultrasonic technique is found to be reliable to measure the elastic moduli, based on the measured values, its eligibility to measure the Poisson’s ratios remains uncertain.

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Tomasz Ozyhar
    • 1
  • Stefan Hering
    • 1
  • Sergio J. Sanabria
    • 2
  • Peter Niemz
    • 1
  1. 1.Institute for Building Materials (Wood Physics)ZurichSwitzerland
  2. 2.Electronics/Metrology/Reliability LaboratorySwiss Federal Laboratories for Materials Science and TechnologyDübendorfSwitzerland

Personalised recommendations