This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling signals and compared them with the original input signal. The factors under investigation in this experiment included: wood type, wood moisture content (MC), input signal frequencies, signal travelling distance and wood condition (wood with/without cracks). The experiment findings demonstrated that higher input signal frequencies results in higher attenuation of acoustic emissions (AE) travelling through the wood. The results also indicate that: wood type, MC, the signal’s travelling distance, and the orientation of the travelling signal, compared to the wood’s grain direction, affected the signal propagation.
Ahmed, B.M., French, J.R.J. and Thorpe, J. (2005) Remedial Treatment of Timber-in-Service. In: VIC, Ed., Study Guide, CRC Wood Innovations, Melbourne, 201.
Panshin, A.J. and Zeeuw, C.D. (1980) Textbook of Wood Technology: Structure, Identification, Uses, and Properties of the Commercial Woods of the United States and Canada. Vol. 1, Graw-Hill Education, New York.
Shmulsky, R. and Jones, P.D. (2011) Forest Products and Wood Science. John Wiley & Sons, Hoboken. https://doi.org/10.1002/9780470960035
Wiedenhoeft, A.C. and Miller, R.B. (2005) Structure and Function of Wood. CRC Press, Boca Raton.
Brodie, G. (2007) Microwave Treatment Accelerates Solar Timber Drying. American Society of Agricultural and Biological Engineers.
Kettunen, P.O. (2006) Wood Structure and Properties. Trans Tech Publications Ltd., Stäfa.
Brodie, G. (2004) Microwaves Speed up Solar Wood Drying. Resource: Engineering & Technology for a Sustainable World, 11, 9.
de la Rosa, J.J.G. (2005) An Application of the Independent Component Analysis to Monitor Acoustic Emission Signals Generated by Termite Activity in Wood. Measurement, 37, 63-76. https://doi.org/10.1016/j.measurement.2004.08.002
Eitzen, D. and Wadley, H. (1984) Acoustic Emission: Establishing the Fundamentals. Journal of Research of the National Bureau of Standards, 89, 75-100. https://doi.org/10.6028/jres.089.008
Grosse, C.U. and Ohtsu, M. (2008) Acoustic Emission Testing. Springer, Berlin. https://doi.org/10.1007/978-3-540-69972-9
Kanji, O. (2012) Acoustic Emission. In: McGraw-Hill Encyclopedia of Science & Technology, McGraw-Hill Education, New York.
Landis, E.N. (2008) Acoustic Emissions in Wood. In: Grosse, C. and Ohtsu, M., Eds., Acoustic Emission Testing, Springer, Berlin, Heidelberg, 311-322. https://doi.org/10.1007/978-3-540-69972-9_12
Keprt, J. and Benes, P. (2009) The Determination of Uncertainty in the Calibration of Acoustic Emission Sensors. International Journal of Microstructure and Materials Properties, 4, 85-103. https://doi.org/10.1504/IJMMP.2009.028435
Jakieła, S., Bratasz, Ł. and Kozłowski, R. (2007) Acoustic Emission for Tracing the Evolution of Damage in Wooden Objects. https://ezp.lib.unimelb.edu.au/login?url=https://search.ebscohost.com/login.aspx?direct=true&db=edsjsr&AN=edsjsr.20619490&site=eds-live&scope=site
Mankin, R. (2011) Perspective and Promise: A Century of Insect Acoustic Detection and Monitoring. American Entomologist, 57, 30-44.
Kloiber, M., Reinprecht, L., Hrivnák, J. and Tippner, J. (2016) Comparative Evaluation of Acoustic Techniques for Detection of Damages in Historical Wood. Journal of Cultural Heritage, 20, 622-631. https://doi.org/10.1016/j.culher.2016.02.009
Dündar, T., Wang, X., As, N. and Avci, E. (2013) Assessing the Dimensional Stability of Two Hardwood Species Grown in Turkey with Acoustic Measurements. Proceedings of the 18th International Nondestructive Testing and Evaluation of Wood Symposium, Madison, 24-27 September 2013, 459-468.
Dündar, T., Wang, X., As, N. and Avci, E. (2016) Potential of Ultrasonic Pulse Velocity for Evaluating the Dimensional Stability of Oak and Chestnut Wood. Ultrasonics, 66, 86-90. https://doi.org/10.1016/j.ultras.2015.11.007
Chopra, S. and Tsoumis, G.T. (2011) Wood—Acoustic Properties. http://www.britannica.com/EBchecked/topic/647253/wood/26165/Acoustic-properties
Wassilieff, C. (1996) Sound Absorption of Wood-Based Materials. Applied Acoustics, 48, 339-356.
Smardzewski, J. (2014) Experimental Study of Wood Acoustic Absorption Characteristics. Holzforschung, 68, 467. https://doi.org/10.1515/hf-2013-0160
Sakurai, Y. and Skudrzyk, E.J. (1969) Acoustic Properties of Wood. The Journal of the Acoustical Society of America, 46, 124-124. https://doi.org/10.1121/1.1973434
Kasal, B., Lear, G. and Tannert, T. (2011) Stress Waves. In: In Situ Assessment of Structural Timber, Springer, Berlin, 5-24.
Senalik, C.A., Schueneman, G. and Ross, R.J. (2014) Ultrasonic-Based Nondestructive Evaluation Methods for Wood. USDA Forest Service, Forest Products Laboratory. https://doi.org/10.2737/FPL-GTR-235
Gerhards, C.C. (1982) Longitudinal Stress Waves for Lumber Stress Grading: Factors Affecting Applications: State of the Art. Forest Products Journal, 32, 20-25.
Sakai, H., Minamisawa, A. and Takagi, K. (1990) Effect of Moisture Content on Ultrasonic Velocity and Attenuation in Woods. Ultrasonics, 28, 382-385. https://doi.org/10.1016/0041-624X(90)90060-2
Minamisawa, A. and Ozawa, A. (1994) Measurement of Moisture Diffusivity in Woods Using Ultrasounds. Journal of the Japan Wood Research Society (Japan), 40, 1052.
Mishiro, A. (1996) Effect of Density on Ultrasonic Velocity in Wood. Mokuzai Gakkaishi, 42, 887-894.
Wilcox, W.W. (1988) Detection of Early Stages of Wood Decay with Ultrasonic Pulse Velocity. Forest Products Journal, 38, 68-73.
Pellerin, R.F., DeGroot, R.C. and Esenther, G.R. (1986) Nondestructive Stress Wave Measurements of Decay and Termite Attack in Experimental Wood Units. Proceedings of the 5th Nondestructive Testing of Wood Symposium, Pullman, 9-11 September 1986, 319-352.
Patton-Mallory, M. and DeGroot, R.C. (1990) Detecting Brown-Rot Decay in Southern Yellow Pine by Acousto-Ultrasonics. 7th International Symposium on Nondestructive Testing of Wood Symposium, Pullman, 29-44.
Bauer, C., Kilbertus, G. and Bucur, V. (1991) Ultrasonic Technique for Determining the Extent of Fungus Attack of Beech and Pine Wood. Holzforschung.
Lemaster, R.L. and Wilcox, W. (1993) The Use of Acousto-Ultrasonics to Detect Decay in Wood-Based Products. 2nd International Conference on Acousto-Ultrasonics, Atlanta, 188-190.
Beall, F. (1994) Acoustic Emission from Oriented Strandboard during Flexural Testing. Proceedings of Progress in Acoustic Emission, Vol. 7, Sopporo, 148.
Beall, F. (2002) Overview of the Use of Ultrasonic Technologies in Research on Wood Properties. Wood Science and Technology, 36, 197-212. https://doi.org/10.1007/s00226-002-0138-4
Bucur, V. and Feeney, F. (1992) Attenuation of Ultrasound in Solid Wood. Ultrasonics, 30, 76-81. https://doi.org/10.1016/0041-624X(92)90037-M
Senalik, C.A., Schueneman, G. and Ross, R.J. (2015) Ultrasonic-Based Nondestructive Evaluation Methods for Wood. Nondestructive Evaluation of Wood, 238, 21.
Reiterer, A., Stanzl-Tschegg, S. and Tschegg, E. (2000) Mode I Fracture and Acoustic Emission of Softwood and Hardwood. Wood Science and Technology, 34, 417-430. https://doi.org/10.1007/s002260000056
Zombori, B. (2001) In Situ Nondestructive Testing of Built in Wooden Members. NDT.net, Vol. 6, 212.