DEFECT DETECTION AND QUALITY ASSESSMENT OF HARDWOOD LOGS: PART 1—ACOUSTIC IMPACT TEST AND WAVELET ANALYSIS
Keywords:
Acoustic velocity, board grade, damping ratio, impact test, log defects, dynamic modulus of elasticity, time centroid, yellow-poplar.Abstract
The objective of this study was to determine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve the accuracy of defect detection and quality assessment in hardwood logs. This article (Part 1) focused on exploring the potential of an acoustic impact testing method coupled with advanced waveform analysis to detect internal decay of hardwood logs and classify logs in terms of log quality and potential board grade yields. Twenty-one yellow-poplar (Liriodendron tulipifera) logs obtained from the Central Appalachian region were evaluated for internal soundness using an acoustic impact testing technique. These logs were then sawn into boards, and the boards were visually graded based on National Hardwood Lumber Association grading rules. The response signals of the logs from acoustic impact tests were analyzed through moment analysis and continuous wavelet transform to extract time-domain and frequency-domain parameters. The results indicated that the acoustic impact test coupled with wavelet analysis is a viablemethod to evaluate the internal soundness of hardwood logs. Log acoustic velocity alone was able to identify the very low-end logs that have the most severe internal rot or other unsound defects but failed to identify the logs with poor geometry that resulted in very low recovery. Time centroid, damping ratio, and combined time- and frequency-domain parameters were found effective in predicting log quality in terms of board grade yields. Log segregation based on time-domain (time centroid and ρ/Tc**2) and frequency-domain (damping ratio and Ed/ζ**2) parameters showed a positive correlation with the board grade yields.
References
Aratake S, Arima T (1994) Estimation of modulus of rupture
(MOR) and modulus of elasticity (MOE) of lumber
using higher natural frequency of log in pile of logs
II—Possibility of application for Sugi square lumber with
pith. Mokuzai Gakkaishi 40(9):1003-1007.
Aratake S, Arima T, Sakoda T, Nakamura Y (1992) Estimation
of modulus of rupture (MOR) and modulus of
elasticity (MOE) of lumber using higher natural frequency
of log in pile of logs—Possibility of application for Sugi
scaffolding board. Mokuzai Gakkaishi 38(11):995-1001.
Bayissa WL, Haritos N, Thelandersson S (2008) Vibrationbased
structural damage identification using wavelet
transform. Mech Syst Signal Process 22(5):1194-1215.
Bhandarkar S, Faust T, Tang M (1999) CATALOG: A
system for detection and rendering of internal log defects
using computer tomography. Mach Vis Appl 11(4):
-190.
Carmona R, Hwang W, Torr´esani B (1998) Practical timefrequency analysis: Gabor and wavelet transforms, with an implementation in S, 1st edition. Academic Press, Inc., San
Diego, CA. 490 pp.
Carter P, Briggs D, Ross RJ, Wang X (2005) Acoustic testing
to enhance western forest values and meet customer wood
quality needs. PNW-GTR642. USDA Forest Service,
Pacific Northwest Research Station, Portland, OR. pp.
-129.
Chang S (1992) External and internal defect detection to
optimize cutting of hardwood logs and lumber. Transferring
Technologies for Industry No. 3. U.S. Department
of Agriculture, National Agriculture Library, Beltsville,
MD. 24 pp.
Delprat N, Escudie B, Guillemain P, Kronland-Martinet R,
Tchamitchian P, Torresani B (1992) Asymptotic wavelet
and Gabor analysis: Extraction of instantaneous frequencies.
IEEE Trans Inf Theory 38(2):644-664.
Gaunt D (2012) A revolution in structural timber grading in
World Conference on Timber Engineering, July 16-19,
, Auckland, New Zealand. 8 pp.
Grossmann A, Morlet J (1984) Decomposition of hardy
functions into square integrable wavelets of constant
shape. SIAM J Math Anal 15:723-736.
Guddanti S, Chang S (1998) Replicating sawmill sawing
with topsaw using CT images of a full length hardwood
log. Forest Prod J 48(1):72-75.
Harris P, Petherick R, AndrewsM(2002) Acoustic resonance
tools. Pages 195-201 in Proc. 13th International Symposium
on Nondestructive Testing of Wood, August 19-21,
, Berkeley, CA. Forest Products Society, Madison,
WI.
Kronland-Martinet R, Morlet J, Grossmann A (1987)
Analysis of sound patterns through wavelet transforms. Int
J Pattern Recognit Artif Intell 1(2):273-302.
Le T, Paultre P (2013) Modal identification based on the
time-frequency domain decomposition of unknown-input
dynamic tests. Int J Mech Sci 71:41-50.
Li P, Abbott A, Schmoldt D (1996) Automated analysis of
CT images for the inspection of hardwood log. Pages
-1749 in Proc. IEEE Conference on Neural Networks.
June 3-6, 1996, Washington, DC.
Mallat S (1999) A wavelet tour of signal processing, 2nd
edition. Academic Press, New York, NY.
Murphy G, Cown D (2015) Sand, stem and log segregation
based on wood properties: a review. Scand J Fr Res 30(8):
-770.
NHLA (2015) Rules for the measurement and inspection of
hardwood and cypress. National Hardwood Lumber Association, Memphis, TN. 104 pp.
Ross RJ, McDonald KA, Green DW, Schad KC (1997)
Relationship between log and lumber modulus of elasticity.
Forest Prod J 47(2):89-92.
Slavic J, Simonovski I, Boltezar M (2003) Damping identification using a continuous wavelet transform: Application to real data. J Sound Vibrat 262:291-307.
Staszewski WJ (1997) Identification of damping in MDOF
systems using time-scale decomposition. J Sound Vibrat
(2):283-305.
Thomas L, Mili L, Thomas RE, Shaffer CA (2006) Defect
detection on hardwood logs using laser scanning. Wood
Fiber Sci 38(4):682-695.
Thomas RE, Thomas L, Shaffer C (2008) Defect detection
on hardwood logs using high-resolution laser scan data.
Pages 163-167 in Proc. 15th International Symposium on
Nondestructive Testing of Wood, September 10-12, 2007,
Duluth, MN. Natural Resources Research Institute, University
of Minnesota, Duluth, MN.
Tiitta M, Biernacki JM, Beall FC (1998) Acousto-ultrasonic
assessment of internal decay in glulam beams. Wood Fiber
Sci 30:24-37.
Ulker-Kaustell M, Karoumi R (2011) Application of the
continuous wavelet transform on the free vibrations of
a steel-concrete composite railway bridge. Eng Struct 33:
-919.
Wagner F, Taylor F, Ladd D, McMillin C, Roder F (1989)
Ultrafast CT scanning of an oak log for internal defects.
Forest Prod J 39(11/12):62-64.
Wang X (2013) Acoustic measurements on trees and logs: A
review and analysis. Wood Sci Technol 47:965-975.
Wang X, Carter P, Ross RJ, Brashaw BK (2007) Acoustic
assessment of wood quality of raw forest materials—A
path to increased profitability. Forest Prod J 57(5):6-14.
Wang X, Stelzer HE, Wiedenbeck J, Lebow PK, Ross RJ
(2009) Assessing wood quality of borer-infested red oak
logs with a resonance acoustic technique. Wood Fiber Sci
(2):180-193.
Wang X, Verrill S, Lowell E, Ross RJ, Herian VL (2013)
Acoustic sorting models for improved log segregation.
Wood Sci Technol 45(4):343-352.
Wiedenbeck J, Wiemann M, Alderman D, Baumgrass J,
Luppold W (2003) Defining hardwood veneer log quality
attributes. General Technical Report NE-313. U.S. Department
of Agriculture, Forest Service, Northeastern
Research Station, Newtown Square, PA. 36 pp.
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