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Use of Longitudinal Vibration and Visual Characteristics to Predict Mechanical Properties of No. 2 Southern Pine 2 × 8 and 2 × 10 Lumber

F. J.N. Franca, T. S. F.A. França, R. D. Seale, R. Shmulsky


The objective of this study was to evaluate the accuracy of single MOE and MOR and combined mechanical properties with visual characteristics to improve the prediction of 2 x 8 and 2 x 10 No. @ southern pine lumber. This study evaluated the following variables: nondestructive tests, knots (knot diameter ratio [KDR] and knot area ratio), density, and mechanical properties (stiffness [MOE] and strength [MOR]). A total of 486 pieces were used, and linear regression models were constructed using stepwise selects to determine the best variables to estimate the MOE and MOR of southern pine lumber. The best single predictor for MOE and MOR was dynamic MOE (dMOE) followed by density. Among the two knot measurement methods used, the KDR best predicted stiffness and strength. For predicting the MOE, the variables dMOE, density, and KDR. The results showed that the addition of knot measurements to the models is able to improve the prediction of mechanical properties.


knots, dimensional lumber, strength, stiffness, statistical models

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American Forest and Paper Association (AFPA) (2005) National design specification (NDS) for wood construction with commentary and supplement: Design values for wood construction 2005 edition. American Forest & Paper As- sociation, Washington, DC.

American Lumber Standards Committee (ALSC) (2013) American lumber standard committee board of review: Board of review minutes. American Lumber Standards Committee, Germantown, MD.

ASTM (2015a) D 245: Standard practice for establishing structural grades and related allowable properties for vi- sually graded lumber. Annual Book of ASTM Standards, West Conshohoken, PA.

ASTM (2019b) D 4761: Standard test methods for mechanical properties of lumber and wood-base structural material. Annual Book of ASTM Standards, West Conshohoken, PA.

ASTM (2015c) E 1876: Standard test method for dynamic Young’s modulus, shear modulus, and Poisson’s ratio by impulse excitation of vibration. Annual Book of ASTM Standards, West Conshohoken, PA.

ASTM (2015d) D 198: Standard test methods of statics of lumber in structural sizes. Annual Book of ASTM Standards, West Conshohoken, PA.

ASTM (2017e) D 2915: Standard practice for sampling and data-analysis for structural wood and woodbased products. Annual Book of ASTM Standards, West Conshohoken, PA. American Wood Council (AWC) (2012) National design specification® (NDS®) for wood construction. AWC, Leesburg, VA

Bacher M (2008) Comparison of different machine strength grading principles. Pages 183-193 in JV Kuilen and WF Gard, eds. COST E53 Conference, October 29-30, Delft, The Netherlands.

Coyle DR, Klepzig KD, Koch FH, Morris LA, Nowak JT, Oak SW, Otrosina WJ, Smith WD, Gandhi KJ (2015) A review of southern pine decline in North America. For Ecol Manag 349:134-148.

Cunningham K, Barry K, Walkingstick T (2008) Managing loblolly pine stands from A to Z. Publication FSA5023. University of Arkansas Cooperative Extension Service, Little Rock, AR.

Denzler J, Diebold R, Glos P (2005) Machine strength grading—Commercially used grading machines—Current

developments. Pages 9-16 in FW Broker and F Eberswalde, eds. Proc. 14th International Symposium on Nondestructive Testing of Wood, May 2-4, 2005, Hannover, Germany.

Diebold R, Schleifer A, Glos P (2000) Machine grading of structural sawn timber from various softwood and hard- wood species. Pages 139-146 in F Divos, ed. Proc. 12th International Symposium on Nondestructive Testing of Wood, September 13-15, 2000, Sopron, Hungary.

Divos F, Sismandy-Kiss F (2010) Strength grading of structural lumber by portable lumber grading—Effect of knots. Pages 538-544 in D Ridley-Ellis and J Moore, eds. The Future of Quality Control for Wood and Wood Products, May 4-7, 2010, Edinburgh, Scotland.

Divos F, Tanaka T (1997) Lumber strength estimation by multiple regression. Holzforschung 51(5):467-471.

Fakopp (2005) Fast Fourier vibration analyzer user’s guide. Fakopp Enterprise Bt, Fakopp Enterprise Publication, Agfalva, Hungary.

França TSFA, França FJN, Seale RD, Shmulsky R (2018) Bending strength and stiffness of no. 2 grade southern pine lumber. Wood Fiber Sci 50(2):1-15.

França FJN, Seale RD, Shmulsky R, França TSFA (2019a) Modeling mechanical properties of 2 by 4 and 2 by 6 southern pine lumber using longitudinal vibration and visual characteristics. Forest Prod J 68(3):286-294.

França FJN, Seale RD, Shmulsky R, França TSFA (2019b) Assessing southern pine 2x 4 and 2 x6 lumber quality: Longitudinal and transverse vibration. Wood Fiber Sci 51(1):2-15.

Grant DJ, Anton A, Lind P (1984) Bending strength, stiff- ness, and stress-grade of structural Pinus radiata: Effect of knots and timber density. N Z J For Sci 14(3):331-348.

Hanhijarvi A, Ranta-Maunus A (2008) Development of strength grading of timber using combined measurement techniques. Report of the Combigrade-project r phase 2. VTT Publication 686, Espoo, Finland.

Hanhijarvi A, Ranta-Maunus A, Turk G (2005) Potential of strength grading of timber with combined measurement techniques. Report of the Combigrade-project phase 1. VTT Publications 568, Espoo, Finland.

Hoyle RJ (1968) Background to machine stress rating. Forest Prod J 18(4):87-97.

Iniguez G, Esteban M, Barrett JD, Arriaga F (2007) Visual grading of large structural coniferous sawn timber according to Spanish standard UNE 56544. Forest Prod J 57(10):45-50.

Johansson CJ, Brundin J, Gruber R (1992) Stress grading of Swedish and German timber. Swedish National Testing and Research Institute, Building technology, SP Report 1992:23, Boras, Sweden.

Kretschmann DE (2010) Stress grades and design properties for lumber, round timber, and ties. Pages 7-1-7-16 in RJ Ross, ed. Wood Handbook Gen Tech Rep FPL-GTR-190. USDA For Serv Forest Products Laboratory, Madison, WI.

McKeand S, Mullin T, Byram T, White T (2003) Deployment of genetically improved loblolly and slash pine in the south. J Forestry 100(3):32-37.

Nocetti M, Bacher M, Brunetti M, Crivellaro A, Van de Kuilen JG (2010) Machine grading of Italian structural timber: Preliminary results on different wood species. Pages 285–291 in A Ceccotti, ed. Proc 11th World Conference on Timber Engineering, June 20-24, 2000, Riva del Garda, Italy.

Panshin AJ, De Zeeuw C (1980) Textbook of wood technology, 4th edition. McGraw-Hill, New York, NY.

Piter JC, Zerbino RL, Blaß HJ (2004) Machine strength grading of Argentinean eucalyptus grandis. Main grading parameters and analysis of strength profiles according to European standards. Holz als Roh- Werkst 62(1):9-15.

Ross RJ (2015) Nondestructive evaluation of wood, 2nd edition. Gen Tech Rep FPL-GTR-238. USDA For Serv Forest Products Laboratory, Madison, WI. 176 pp.

SAS (2013) SAS Institute Inc. Version 9.4, Cary, NC.

Shapiro SS, Wilk MB (1965) An analysis of variance test for normality (complete samples). Biometrika 52:591-611.

Shmulsky R, Seale RD, Snow RD (2006) Analysis of acoustic velocity as a predictor of stiffness and strength in 5-in-diameter pine dowels. Forest Prod J 56(9): 52-55.

Southern Pine Inspection Bureau (SPIB) (2014) Standard grading rules for southern pine lumber. SPIB, Pensacola, FL. 147 pp.

Vega A, Guaita M, Dieste A, Majada J, Ferna´ndez I, Baño V (2011) Evaluation of the influence of visual parameters on wave transmission velocity in sawn chestnut timber. Pages 311-318 in F Divos, ed. 17th International Nondestructive Testing and Evaluation of Wood Symposium, Sopron, Hungary.

Wear DN, Greis JG (2002) Southern forest resource assessment: Summary of findings. J Forestry 100(7):6-14.

Wright SL (2015) Mapping the effects of knots on loblolly pine lumber. MS thesis, University of Georgia, Athens, GA. 48 pp.

Yang BZ, Seale RD, Shmulsky R, Dahlen J, Wang X (2015) Comparison of nondestructive testing methods for evaluating no. 2 southern pine lumber: Part A, modulus of elasticity. Wood Fiber Sci 47(4):375-384.

Yang BZ, Seale RD, Shmulsky R, Dahlen J, Wang X (2017) Comparison of nondestructive testing methods for evaluating no. 2 southern pine lumber: Part B, modulus of rupture. Wood Fiber Sci 49(2):134-145.


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