Influence of Acoustic Velocity, Density, and Knots on the Stiffness Grade Outturn of Radiata Pine Logs

Authors

  • Trevor G. Jones
  • Grant W. Emms

Keywords:

Acoustic velocity, density, knots, modulus of elasticity, radiata pine

Abstract

The prediction of log-average lumber modulus of elasticity (MOE) from log measurements of acoustic velocity, green density, heartwood content, and branch and whorl variables was evaluated for green and kiln-dried boards of unpruned second and third logs of mature radiata pine. The use of principal component analysis showed there were strong associations between the log acoustic velocity and branch size variables, the number of branches and whorls and mean internode length, and the green density and heartwood content. These relationships were reflected in the regression models that showed good predictions of log-average green and kiln-dried board MOE from log acoustic velocity and green density or heartwood content with only a small contribution from branch and whorl variables.

References

Bodig J, Goodman JR (1973) Prediction of the elastic parameters for wood. Wood Sci 5(4):249-264.nBucur V (1995) Acoustics of wood. CRC Press Inc., Boca Raton, FL. 284 pp.nCown DJ, Walford B, Kimberley MO (1995) Cross-grain effect on tensile strength and bending stiffness of Pinus radiata structural lumber. N Z J Sci 25(2):256-262.nDickson RL, Matheson AC, Joe B, Ilic J, Owen JV (2004) Acoustic segregation of Pinus radiata logs for sawmilling. N Z J Sci 34(2):175-189.nJang SS (2000) Evaluation of lumber properties by applying stress waves to larch logs grown in Korea. Forest Prod J 50(3):44-48.nLittell RC, Milliken GA, Stroup WW, Wolfinger RD (1996) SAS system for mixed models. SAS Institute Inc., Cary, NC. 656 pp.nSandoz JL (1989) Grading of construction timber by ultrasound. Wood Sci Technol 23(1):95-108.nSAS Institute Inc (2000) SAS/STAT user's guide, Version 8, Vols. 1, 2, and 3. SAS Institute Inc., Cary, NC. 1464 pp.nTsehaye A, Buchanan AH, Walker JCF (2000) Sorting of logs using acoustics. Wood Sci Technol 34:337-344.nWatt MS, Moore JR, McKinlay B (2005) The influence of wind on branch characteristics of Pinus radiata.Trees-Struct Funct 19(1):58-65.n

Downloads

Published

2010-01-18

Issue

Number 1 / January 2010

Section

Research Contributions

License

The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:

1. All proprietary rights other than copyright, such as patent rights.

2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.

3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.