Assessing Southern Pine 2x4 and 2x6 Lumber Quality: Longitudinal and Transverse Vibration

Authors

  • F.J.N. França Mississippi State University http://orcid.org/0000-0001-7807-8877
  • R. D. Seale Mississippi State University
  • R. Shmulsky Mississippi State University
  • T.S.F.A. França Mississippi State University

Abstract

A primary goal of structural lumber grading is the identification of the strength-reducing characteristics that impact the modulus of rupture (MOR). Non-destructive evaluation technology can be used to identify material of greater stiffness. This study investigates the use of longitudinal and transverse vibration methods to evaluate the mechanical properties of 2x4 and 2x6 southern yellow pine lumber. A total of 1240 samples were conditioned to 12% equilibrium moisture content. All samples were first non-destructive tested using transverse vibration equipment (Metriguard E-computer) in edgewise and flatwise directions and three different longitudinal vibration devices (Fakopp Portable Lumber Grader, Director HM200, and Falcon A-grader) to obtain the vibration properties using transverse and longitudinal methods. The dynamic modulus of elasticity (MOE) of each sample was calculated based on the fundamental wave equation.  Static bending was subsequently conducted according to ASTM 198 (2012), and the rate of loading followed ASTM D4761 (ASTM 2012). The results showed statistically significant correlations between static MOE and the dynamic MOE measured by non-destructive techniques. Weaker correlations were found between MOR and the dynamic MOE values. Likely this finding is because it is related to the ultimate strength of material, often associated with the existence of localized defects, such as a knot, on the lumber piece. This study indicates that non-destructive techniques can potentially be used to evaluate 2x4 and 2x6 stiffness and improvements can be done for a better evaluation of southern pine lumber.

Author Biographies

F.J.N. França, Mississippi State University

Assistant Research Professor, Department of Sustainable Bioproducts

R. D. Seale, Mississippi State University

Warren S. Thompson Professor, Department of Sustainable Bioproducts

R. Shmulsky, Mississippi State University

Professor and Department Head, Department of Sustainable Bioproducts

T.S.F.A. França, Mississippi State University

Postdoctoral Associate, Department of Sustainable Bioproducts

References

ASTM (2012) D 198: Standard test methods of statics of lumber in structural sizes. Annual Book of ASTM Standards. West Conshohoken, PA.

ASTM (2009) D 1876: Standard Test Method for Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio by Impulse Excitation of Vibration. West Conshohocken, Pennsylvania, USA.

Amishev D, Murphy GE (2008) In-forest assessment of veneer grade Douglas-fir logs based on acoustic measurement of wood stiffness. For Prod J 58(11):42–47.

Brashaw BK, Bucur V, Divós F, Gonçalves R, Lu JX, Meder R, Pellerin RF, Potter S, Ross RJ, Wang X, Yin YF (2009) Nondestructive testing and evaluation of wood: A worldwide research update. For Prod J 59(3):7–14.

Carreira MR (2012) Avaliação da Rigidez à Flexão de Toras de Madeira por meio de Vibração Transverse (Evaluation of bending stiffness of wood logs by meann of transverse vibration). PhD dissertation, Escola de Engenharia de São Carlos, Universidade de São Paulo, Brazil. pp. 385. In Portuguese with summary in English.

Cossolino LC, Pereira AHA (2010) Informativo Técnico-Científico/ATCP Engenharia Física. Módulos elásticos: visão geral e métodos de caracterização. Available at: <http://www.investagro.com.br>. Access in: 4 Jan. 2016. In Portuguese.

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

Divós F, Tanaka T (2005) Relation between Static and Dynamic Modulus of Elasticity of Wood, Acta Silv. Lign. Hung, 1:105-110.

Doyle D V, Markwardt LJ (1966) Properties of southern pine in relation to strength grading of dimension lumber. Res. Pap. FPL-RP-64. USDA For Serv Forest Products Laboratory, Madison, WI. 62 pp.

Fakopp Enterprise Bt (2005) Fast Fourier Vibration analyzer User’s Guide. Fakopp Enterprise publication. Hungary.

Gerhards CC (1982) Longitudinal stress waves for lumbers stress grading: Factors affecting applications: State of art. For Prod J. 32(20):20-25.

Green DW, McDonald KA (1993) Investigation of the mechanical properties of red oak 2 by 4’s. Wood and Fiber Sci. 25(1): 35–45.

O’Halloran MR (1972) Nondestructive parameters of lodgepole pine dimension lumber. For Prod J 22(2):44–51.

Pellerin RF (1965) A vibrational approach to nondestructive testing of structural lumber. For Prod J 15(3): 93–101.

Porter AW, Kusec DJ, Olson SL (1972) Digital computer for determining modulus of elasticity of structural lumber. WFPL Info. Rep. VP-X-99. Vancouver, BC: Department of Environment, Canadian Forest Service.

Ross RJ, Geske EA, Larson GH, Murphy JF (1991) Transverse Vibration Nondestructive Testing Using a Personal Computer. Res. Pap. FPL-RP-502. USDA For Serv Forest Products Laboratory, Madison, WI. 17 pp.

SAS Institute (2013) SAS® software, version 9.4. The SAS Institute Inc. Cary, NC.

Shmulsky R, Selae 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.

Vega A, Guaita M, Dieste A, Majada J, Fernández I, Baño V (2011) Evaluation of the influence of visual parameters on wave transmission velocity in sawn chestnut timber.

Pages 311–318 in F Divós, eds. 17th International Nondestructive Testing and Evaluation of Wood Symposium, September 14-16, 2011, University of West Hungary, Sopron, Hungary.

Wang X (2013) Stress Wave E-Rating of Structural Timber—Size and Moisture Content Effects. Pages 38–46 in Ross RJ, Wang, X, eds. Proceedings 18th International Nondestructive Testing and Evaluation of Wood Symposium, September 24–27, 2013, Madison, WI, Forest Prod Soc, Madison WI.

Wang Z, Ross RJ, Murphy JF (1993) A comparison of several NDE techniques for determining the modulus of elasticity of lumber. Wood Forestry Research. 6(4): 86-88.

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.

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Published

2019-01-27

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