Prediction of Bending Strength in Oak Beams on the Basis of Elasticity, Density, and Wood Defects
Publication: Journal of Materials in Civil Engineering
Volume 24, Issue 6
Abstract
The purpose of the study was to propose accurate models for predicting bending strength that are valid for a wide range of beam qualities. For the study, 26 European oaks (Quercus robur L.) were felled in northwestern Spain, where most of the oak stands in the country are located. The trees were sawn, and a sample of quarter-sawn planks was selected. Planed and edged specimens () were tested to obtain the modulus of rupture (MOR) in axial direction bending, the modulus of elasticity (MOE), density, moisture content, and size of defects. The MOR was correlated with the MOE and with maximum edge knot diameter. The correlation was not high enough to justify construction of a predictive model of mechanical behavior on the basis of maximum knot size in the piece. The analyses enabled development of a model for predicting MOR, with MOE as the only predictor variable (; ).
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
We thank the Xunta de Galicia and the Research Office of the Universidad de Santiago de Compostela for providing financial support for the project.
References
Breyer, D. E., Fridley, K. J., Cobeen, K. E., and Pollock, D. G. (2007). Design of wood structures-ASD/LRFD, McGrawHill Inc, NY.
Castéra, P., and Toratti, T. (1999). “Probabilistic treatments of mechanical properties of wood.” In: COST Action 508 Wood Mechanics, Final report of activity, Morlier, P., and Castéra, P., eds., Management Committee, Stuttgart, Germany.
Chui, Y. H. (1991). “Simultaneous evaluation of bending and shear moduli of wood and the influence of knots on these parameters.” Wood Sci. Technol.WOSTBE, 25(2), 125–134.
Collardet, J., and Besset, J. (1992). Bois commerciaux (vol. II). Feuillus des zones tempérées, H. Vial and CTBA, France.
Courchene, T., Lam, F., and Barrett, J. D. (1998). “The effect of edge knots on the strength of SPF MSR lumber.” For. Prod. J.FPJOAB, 48(4), 75–81.
Desch, H. E., and Dinwoodie, J. M. (1996). Timber. Structure, properties, conversion and use, MacMillan Press Ltd., Hong-Kong.
European Committee for Standardization. (2002). “Moisture content of a piece of sawn timber—Part 1: Determination by oven dry method.” EN 13183-1:2002, CEN, Brussels.
European Committee for Standardization. (2003). “Structural timber. Strength classes.” EN 338:2003, CEN, Brussels.
European Committee for Standardization. (2004a). “Structural timber. Determination of characteristic values of mechanical properties and density.” EN 384:2004, CEN, Brussels.
European Committee for Standardization. (2004b). “Timber structures. Structural timber and glued laminated timber. Determination of some physical and mechanical properties.” EN 408:2004, CEN, Brussels.
Evans, J. W., Evans, J. K., and Green, D. W. (1990). “Computer programs for adjusting the mechanical properties of 2-inch dimension lumber for changes in moisture content.” General Technical Report FPL-GTR-63, USDA Forest Service, Forest Products Laboratory, Madison, Wis.
Farmer, R. H. (1972). “Handbook of hardwoods.” Her Majesty’s Stationery Office, London.
Freas, A. D. (1995). “Wood properties.” In: Wood engineering and construction handbook, Faherty, K. F. and Williamson, T. G., eds., McGrawHill Inc, NY.
Green, D. W., and Evans, J. W. (1988). “Evaluating lumber properties: practical concerns and theoretical restraints.” Proc. of the 1988 Int. Conf. on Timber Engineering, vol. I, Forest Products Research Society, Seattle, 203–217.
Green, D. W., and McDonald, K. A. (1993). “Investigation of the mechanical properties of red oak 2 by 4’s.” Wood Fiber Sci.WFSCD4, 25(1), 35–45.
IBM. (2010). 〈http://www.spss.com/〉.
International Organization for Standardization. (1975). “Wood. Determination of density for physical and mechanical tests.” ISO 3131:1975, ISO, Geneva.
McLeod, J. A. III, and McLain, T. E. (1987). “Evaluation of bending strength ratios for eastern oak pallet lumber.” Wood Fiber Sci.WFSCD4, 19(3), 269–282.
Ministerio de Medio Ambiente, y Medio Rural y Marino. (2009). “Anuario de Estadística Agroalimentaria y Pesquera 2008.” Madrid.
Mitre, E. M. (1988). “Los sistemas constructivos de la madera.” IV Jornadas nacionales de la madera en la construcción, Agrupación Nacional de Constructores de Obras, Madrid.
Nassar, D. (1996). “La construcción de madera en España.” El campo: boletín de información agraria, 134, 295–302.
Riesco, G. (2001). “Estudio de las propiedades físico-mecánicas de la madera de roble (Quercus robur L.) de Galicia en relación con las variables del medio.” Doctoral Thesis, Universidad Politécnica de Madrid.
Schaffer, E. L. (1995). “Preliminary design considerations.” Wood engineering and construction handbook, Faherty, K. F. and Williamson, T. G., eds., McGrawHill, Inc, NY.
Shanks, J., and Walker, P. (2009). “Strength and stiffness of all-timber pegged connections.” J. Mater. Civ. Eng.JMCEE7, 21(1), 10–18.
UNECE/FAO. (2009). “Forest products annual market review, 2008-2009.” Geneva Timber and Forest Study Paper 24, United Nations, NY and Geneva.
Xunta de Galicia (2001). “O bosque galego en cifras.” Consellería de Medio Ambiente, Santiago de Compostela.
Yeomans, D. T. (1999). “The problems of assessing historic timber strengths using modern design codes.” In: The use of and need for preservation standards in architectural conservation, Sickels-Taves, L. B., ed., ASTM STP 1355, American Society for Testing and Materials, West Conshohocken, Pa.
Zhang, S. Y., Nepveu, G., and Owoundi, R. E. (1994). “Intratree and intertree variation in selected wood quality characteristics of European oak (Quercus petraea and Quercus robur).” Can. J. For. Res.CJFRAR, 24(9), 1818–1823.
Information & Authors
Information
Published In
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Jul 2, 2010
Accepted: Nov 14, 2011
Published online: Nov 16, 2011
Published in print: Jun 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.