Non-destructive testing methods for lumber

Details Non-destructive testing methods for lumber Non-destructive testing methods for lumber

1987-09-14

1990-05-15

Lall, P.S.

Boots, shoes, and leggings

36447409, 734321, 209517, 250563, 356445, G01R 2700, G01N 2100, B07C 514

Patent

active

049263501

ABSTRACT:
A non-destructive testing system for lumber involves measurement of grain angle about a board and transformation of the measured grain angle values to extract features indicative of knot identification, grain angle perturbations or strength of the board. Individual boards can then be processed for grading or sorting purposes as a function of the extracted features. Specific features utilized for knot identification are curl, divergence, and novel transformations termed gradient, edges and knots, as well as various pattern matching techniques. Strength estimation involves transformations pertaining to failure distance, which is a function of board tensile strength. Failure distance can be computed by an ellipsoidal model, a search model or a tracks model. When utilized in conjunction with conventional bending test procedures, highly accurate strength estimation is achieved by the described system.

REFERENCES:
patent: 3194063 (1965-07-01), McKean
patent: 3196672 (1965-07-01), Keller
patent: 3805156 (1974-04-01), Norton et al.
patent: 3942021 (1976-03-01), Barr et al.
patent: 3976384 (1976-08-01), Matthews et al.
patent: 4017976 (1977-04-01), Barr et al.
patent: 4195346 (1980-03-01), Schroder
patent: 4207472 (1980-06-01), Idelsohn et al.
patent: 4221974 (1980-09-01), Mueller et al.
patent: 4372163 (1983-02-01), Tittmann et al.
patent: 4500835 (1985-02-01), Heikkila
patent: 4514816 (1985-04-01), Ollus et al.
patent: 4606645 (1986-08-01), Matthews et al.
patent: 4607212 (1986-08-01), Jakkula
patent: 4789820 (1988-12-01), Parrent, Jr. et al.
Cramer, Steven M. and Goodman, James R., 1985, Predicting Tensile Strength of Lumber, Fifth Nondestructive Testing of Wood Symposium, WSU, Pullman, Wash., pp. 525-545.
McDonald, Kent and Bendtsen, B. Alan, 1985, Measuring Localized Slope of Grain by Electronic Capacitance, Forest Prod. J, 36 (10): 75-76.
McLauchlan, T. A. and Kusec, D. J., 1978, Continuous Non--Contact Slope--of--Grain Detection, Fourth Nondestructive Testing of Wood Symposium, WSU Engineering Extension Service Pullman, Wash., Vancouver, Wash., pp. 67-76.
McLauchlan, T. A.; Norton, J. A. and Kusec, D. J., 1973, Slope--of--Grain Indicator, Forest Prod. J., 23(5): 50-55.
Samson, Marcel, 1984, Measuring General Slope of Grain with the Slope of Grain Indicator, Forest Prod. J. 34(7/8): 27-32.
McDonald, Kent and Bendtsen, 1985, Localized Slope--of--Grain Its Importance and Measurement, Fifth Nondestructive Testing of Wood Symposium, Washington State University, Pullman, Wash., pp. 477-489.
Goodman, James R. and Bodig, Jozsef, 1978, Mathematical Model of the Tension Behavior of Wood with Knots and Cross Grain, Proceedings, First International Conference on Wood Fracture, Banff, Alberta, pp. 53-61.
Metriguard Brochure: Grain Slope Measurement with the Metriguard 5100 Slope--of--Grain--Indicator.
Metriguard Brochure: CLT--Continuous Lumber Tester.

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