Anisotropic Stiffness Tensor Measurement for Standing Trees using Acoustics

Acoustic non-destructive testing techniques have been developed to measure properties, such as stiffness, of standing trees and logs. Standing tree stiffness measurements are commonly calculated by inserting two probes into the “same face” of the tree stem, hitting one with a hammer, and measuring the propagation time of the resulting acoustic signal between two probes. Studies have suggested that these time of flight measurements are biased to measure the outerwood stiffness rather than that of the tree stem as a whole and may vary between different hammer hit strengths and hence between users. In this paper, we explore a multipath acoustic technique for measuring components of the anisotropic stiffness matrix of tree stems, which describes the mechanical properties of wood. This technique uses anisotropic acoustic wave propagation velocity measurements made along the surface and through a standing tree. This technique was used to calculate an average stiffness through the tree’s cross-section. Different acoustic/ultrasonic excitation techniques are investigated which obtain velocity measurements that are independent of the user.

References
  • Andrews, M., 2002. Which acoustic speed. In: Proceedings of the 13th International Symposium on Nondestructive Testing of Wood. pp.159–165.
  • Bucur, V., 2006. Acoustics of wood. 2nd ed. New York: Springer.
  • Carcione, J.M., 2007a. Anisotropic elastic media. In: Wave fields in real media: Wave propagation in anisotropic, anelastic, porous and electromagnetic media. Oxford, Elsevier.
  • Chauhan, S. and Walker, J., 2006. Variations in acoustic velocity and density with age, and their interrelationships in radiata pine. Forest Ecology and Management, 229(1), pp.388–394.
  • Dickson, R., Matheson, A., Joe, B., Ilic, J. and Owen, J., 2004. Acoustic Segregation of Pinus radiata logs for sawmilling. New Zealand Journal of Forestry Science, 34(2), pp.175–189.
  • Dickson, R.L., Raymond, C.A., Joe, W. and Wilkinson, C.A., 2003. Segregation of Eucalyptus dunnii logs using acoustics. Forest Ecology and Management, 179(1), pp.243–251.
  • Dikrallah, A., Hakam, A., Kabouchi, B., Brancheriau, L., Baillères, H., Famiri, A. and Ziani, M., 2006. Experimental analysis of acoustic anisotropy of green wood by using guided waves. Proceedings of the ESWM-COST Action E, 35, pp.149–154.
  • Grabianowski, M., Manley, B. and Walker, J., 2006. Acoustic measurements on standing trees, logs and green lumber. Wood Science and Technology, 40(3), pp.205–216.
  • Harris, P., Petherick, R. and Andrews, M., 2002. Acoustic resonance tools. In: Proceedings, 13th International Symposium on Nondestructive Testing of Wood. pp.195–201.
  • Hsu, C.Y., 2003. Radiata pine wood anatomy structure and biophysical properties. PhD thesis, Forestry Department, University of Canterbury, New Zealand.
  • Joe, B., Dickson, R., Raymond, C., Ilic, J. and Matheson, A., 2004. Prediction of Eucalyptus Dunnii and Pinus Radiata Timber Stiffness Using Acoustics: A Report for the RIRDC/Land and Water Australia/FWPRDC/MDBC Joint Venture Agroforestry Program. RIRDC.
  • Lasserre, J.-P., Mason, E.G. and Watt, M.S., 2007. Assessing corewood acoustic velocity and modulus of elasticity with two impact based instruments in 11-year-old trees from a clonal-spacing experiment of Pinus radiata D. Don. Forest Ecology and Management, 239(1), pp.217–221.
  • Legg, M and S Bradley. Measurement of stiffness of standing tress using acoustic velocity measurements made through tree stems. In 19th International Nondestructive Testing and Evaluation of Wood Symposium, pages 633–640. Rio de Janeiro, Brazil, 22–25 Sep. 2015.
  • Li, G., Wang, X., Feng, H., Wiedenbeck, J. and Ross, R.J., 2014. Analysis of wave velocity patterns in black cherry trees and its effect on internal decay detection. Computers and Electronics in Agriculture, 104, pp.32–39.
  • Mahon, J.M., 2007. The use of acoustics for the wood quality assessment of standing P. taeda trees. PhD Thesis. University of Georgia.
  • Mahon, J.M., Jordan, L., Schimleck, L.R., Clark, A. and Daniels, R.F., 2009. A comparison of sampling methods for a standing tree acoustic device. Southern Journal of Applied Forestry, 33(2), pp.62–68.
  • Matheson, A.C., Dickson, R.L., Spencer, D.J., Joe, B. and Ilic, J., 2002. Acoustic segregation of Pinus radiata logs according to stiffness. Annals of Forest Science, 59(5-6), pp.471–477.
  • Maurer, H., Schubert, S.I., Bächle, F., Clauss, S., Gsell, D., Dual, J. and Niemz, P., 2006. A simple anisotropy correction procedure for acoustic wood tomography. Holzforschung, 60(5), pp.567–573.
  • Mora, C.R., Schimleck, L.R., Isik, F., Mahon, J.M., Clark, A. and Daniels, R.F., 2009. Relationships between acoustic variables and different measures of stiffness in standing Pinus taeda trees. Canadian Journal of Forest Research, 39(8), pp.1421–1429.
  • Ross, R.J. and Pellerin, R.F., 1994. Nondestructive testing for assessing wood members in structures. General Technical Report FPL-GTR-70, Forest Products Laboratory, US Department of Agriculture.
  • Searles, G., 2012. Acoustic segregation and structural timber production. PhD thesis. Edinburgh Napier University.
  • Su, J., Zhang, H. and Wang, X., 2009. Stress Wave Propagation on Standing Trees-Part 2. Formation of 3D Stress Wave Contour Maps. In: Series: Conference Proceedings.
  • Svilainis, L. and Motiejunas, G., 2006. Power amplifier for ultrasonic transducer excitation. Ultragarsas, 1(58), pp.30–36.
  • Wang, X., 2013. Acoustic measurements on trees and logs: a review and analysis. Wood Science and Technology, 47(5), pp.965–975.
  • Wang, X., Ross, R.J. and Carter, P., 2007. Acoustic evaluation of wood quality in standing trees. Part I. Acoustic wave behavior. Wood and Fiber Science, 39(1), pp.28–38.
  • Wang, X., Ross, R.J., McClellan, M., Barbour, R.J., Erickson, J.R., Forsman, J.W. and McGinnis, G.D., 2001. Nondestructive evaluation of standing trees with a stress wave method. Wood and Fiber Science, 33(4), pp.522–533.
  • Wang, X.R.R.J., Brashaw, B.K., Punches, J., Erickson, J.R., Forsman, J.W. and Pellerin, R.F., 2004. Diameter effect on stress-wave evaluation of modulus of elasticity of logs. Wood and Fiber Science, 36(3), pp.368–377.
  • Zhang, H., Thurber, C. and Rowe, C., 2003. Automatic P-wave arrival detection and picking with multiscale wavelet analysis for single-component recordings. Bulletin of the Seismological Society of America, 93(5), pp.1904–1912.
  • Zhang, H., Wang, X. and Ross, R.J., 2009. Stress wave propagation on standing trees: Part 1. Time-of-flight measurement and 2D stress wave contour maps. In: 16th International Symposium on NDT/NDE of Wood. Beijing, China, pp.12–14.
  • Zhang, H., Wang, X. and Su, J., 2011. Experimental investigation of stress wave propagation in standing trees. Holzforschung, 65(5), pp.743–748.
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