Composite Model Prediction of Elastic Moduli for Flakeboard
Keywords:
Flakeboard, model prediction, MOE, resin contentAbstract
The objective of this research was to develop a model to predict the flexural modulus of elasticity of oriented flakeboards. Variables incorporated into the model included flake geometry, flake orientation, density, resin content, and species. Verification of the model was accomplished by comparing predictions with flexural modulus of elasticity (MOE) values measured parallel and perpendicular to the flake alignment direction of 192 specimens made from two species (Populus grandidentata, Michx. and Acer rubrum) at 4 resin levels (3, 5, 7 and 9%) and 3 target densities (35, 42, and 52 pcf). Use of the longitudinal Halpin-Tsai equations in conjunction with measured and estimated wood and resin properties, predicted the moduli of aspen and red maple flakeboard specimens with a standard error of estimate of 93,985 psi, a coefficient of determination of 89.5%, and an average of 25% below experimental values. The statistical correlations were influenced by grouping of data using flake alignment direction and species. Important issues of vertical density gradient, inhomogeneities, and resin compatibility were not accounted for. The approach was easily computed and gave reasonably accurate predictions of elastic moduli of a single oriented flakeboard manufactured over a range of resin levels, density, alignment, flake geometry, and species conditions.References
Adams, R. D., and N. S. Peppiatt. 1974. Stress analysis of adhesive bonded lap joints. J. Strain Analysis 9(3):185-196.nAgarwal, B. D., and C. J. Broutman. 1980. Analysis and performance of fiber composites. John Wiley and Sons, New York. 355 pp.nAmerican Society of Testing and Materials. 1987. Standard methods of testing small clear specimens of timber. ASTM D143-83. Philadelphia, PA.nBodig, J., and J. R. Goodman. 1973. Prediction of elastic parameters for wood. Wood Sci. 5(4): 249-264.nBrown, T. D. 1975. Modeling of strength and physical properties of structural-type particleboard. Ph.D. dissertation, Colorado State University, Ft. Collins, CO. 126 pp.nGeimer, R. L., W. F. Lehmann, and J. D. McNatt. 1974. Engineering properties of structural panicleboards from forest residues. Pages 119-143 in T. M. Maloney, ed. Proceedings of eight Washington State University symposium on particleboard. Pullman, Washington.nGeimer, R. L. 1986. Mechanical property ratios: A measure of flake alignment. Madison, WI. USDA, Forest Products Lab. Res. Pap. 468. 10 pp.nHalpin, J. C., and S. W. Tsai. 1969. Effects of environmental factors on composite materials. AFML-TR 67-423.nHalpin, J. C., and J. L. Kardos. 1976. The Halpin-Tsai equations: A review. Polymer Eng. Sci. 16(5): 344-352.nHarris, R. A. 1977. Measuring particle alignment in particleboard and predicting selected mechanical properties of oriented boards. Ph.D. dissertation, Virginia Polytechnic Institute and State University. 73 pp.nHashin, Z. 1983. Analysis of composite materials—a survey. J. Appl. Mech. 50(9):281-505.nHunt, M. O. 1972. Finite element analysis of flakeboard. Pages 287-298 in B. A. Jayne, ed. Theory and design of wood and fiber composite materials. Syracuse University Press.nHunt, M. O., W. L. Hoover, R. C. Lattanzi, and J. A. Youngquist. 1985. A design approach for mixed hardwood structural flakeboard. Pages 164-172 in Doris Robertson, coord. Structural wood composites: Meeting today's needs and tomorrow's challenges. Proceedings 7339, November 12-14, 1984, Minneapolis, MN. Forest Products Research Society.nJones, R. M. 1972. Mechanics of composite materials. McGraw-Hill, New York. 355 pp.nLau, P.W. C. 2982. Numerical approach to predict the modulus of elasticity of oriented waferboard. Wood Sci. 14(2):73-85.nMarkwardt, L. J., and T. R. C. Wilson. 1935. Strength and related properties of wood grown in the United States. USDA Tech. Bull. No. 479. Washington, DC.nRussell, W. B. 1973. On the effective moduli of composite materials: Effect of fiber length and geometry at dilute concentrations. J. Appl. Math and Physics (ZAMP) 24(5):581-600.nSalmen, L., and A. deRuvo. 1985. A model for the prediction of fiber elasticity. Wood Fiber Sci. 17(3):336-350.nSchneider, A. 1982. Investigations on the pore structure of particleboard by means of mercury porosimetry. Holz Roh- Wrkst. 40(2):415-420.nShaler, S. M. 1986. The usefulness of selected polymer composite theories to predict the elastic moduli of oriented flakeboard. Ph.D. dissertation, Pennsylvania State Univ., University Park, PA. 163 pp.nSiau, J. 1984. Transport processes in wood. Springer-Verlag, New York, NY. 245 pp.nWellons, J. D. 1983. The adherends. Pages 86-134 in R. F. Blomquist et al., eds. Adhesive bonding of wood and other structural materials, vol. 2. EEMSE. Pennsylvania State Univ. Press.nWu, T. T. 1966. The effect of inclusion shape on the elastic moduli of a two-phase material. Int. J. Solids Struct. 291:1-8.nZar, J. H. 1984. Biostatistical analysis. 2nd ed. Prentice-Hall, Inc. New York, NY. 718 pp.n
Downloads
Published
Issue
Section
License
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.
