Ultrasonic Detection of Knots and Annual Ring Orientation in Pinus Radiata Lumber
Keywords:
Ultrasonic waves, knot detection, growth ring angleAbstract
An ultrasonic defect detection system for radiata pine lumber based on 0.5 Mhz sound transmission through wood was tested. The feasibility of detecting knots, grain deviation, and growth ring angle with this system was investigated as well. The knot material, area of knot influence, and growth ring angle were significantly correlated to wave velocity. The ultrasonic scanning showed good agreement with visual prediction.References
Biernacki, J. M., and F. C. Beall. 1993. Development of an acoustic ultrasonic scanning system for nondestructive evaluation of wood and wood laminates. Wood Fiber Sci. 25(3):289-297.nBucur, V. 1987. Wood characterization through ultrasonic waves. Pages 323-342 in A. Alippi and W. G. Mayer, eds. Ultrasonic methods in the evaluation of inhomogeneous materials. Martinus Nijhoff Publ., Dordrecht, Boston, Lancaster.nBucur, V. 1995. Acoustic of wood. CRC Press, Inc., Boca Raton, FL 284 pp.nBucur, V., and R. R. Archer. 1984. Elastic constants for wood by an ultrasonic method. Wood Sci. Technol. 18:255-265.nChazelas, J. L., A. Vergne, and V. Bucur. 1988. Analyse de la variation des propiétés physiques et mécaniques locales du bois autor des noeuds. Pages 376-386 in Actes du colloque comportement mechanique du bois. June 8-9, Bordeaux, France.nMcDonald, K. A. 1978. Lumber defect detection by ultrasonics. Res. Pap. No. FPL 311. USDA, Forest Prod. Lab., Madison, WI.nPhillips, G. E., J. Bodig, and J. R. Goodman. 1981. Flow grain analogy. Wood Sci. 14(2):55-64.nSandoz, J. L. 1989. Grading of construction timber by ultrasound. Wood Sci. Technol. 23:95-108.nSandoz, J. L. 1993. Moisture content and temperature effect on ultrasound timber grading. Wood Sci. Technol. 27:373-380.nSzymani, R., and K. A. McDonald. 1981. Defect detection in lumber: State of the art. Forest Prod. J. 31(11):34-44.n
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