Tapered Double Cantilever Beam Fracture Tests of Phenolic-Wood Adhesive Joints
Keywords:
Tapered double cantilever beam, fracture energy, bondline thickness, grain angle, cure time, phenol-resorcinolAbstract
Tapered double cantilever beam specimens were developed and used to test the effects of bondline thickness, wood anisotropy, and cure time on the fracture energy of phenolic-wood adhesive joints. Fracture, energy, G10, increases slowly with bondline thickness (in the range 160-100 microns) then jumps considerably (100-90 microns), and finally drops sharply at bondline thicknesses less than 70 microns. As the grain orientation with respect to the bonded surface (grain angle) is increased from zero degrees, G10 decreases and goes through a minimum at about 20 degrees grain angle. At larger grain angles, G10 increases. The fracture energy also increases strongly with cure time, reaching a plateau at long cure times.References
Bascom, W. D., R. D. Cottington, and R. L. Jones, 1975. The fracture of epoxy and elastomer-modified epoxy polymers in bulk and as adhesives. J. Appl. Polym. Sci. 19:2542-2562.nBennett, S. J., K. L. DeVries, and M. L. Williams, 1974. Adhesive fracture mechanics. Int. J. Fracture 10:33-43.nCottrell, A. M. 1959. Theoretical aspects of fracture. Technology Press. New York.nGledhill, R. A., and A. J. Kinloch, 1974. Environmental failure of structural adhesive joints. J. Adhesion 6:315-330.nGotdon, J. E. 1976. The new science of strong materials, Penguin: New York. pp 112-120.nGriffith, A. A. 1920. The phenomena of rupture and flow in solids. Trans. Roy. Soc. London A221:163-198.nIrwin, G. R. 1958. Fracture—Encyclopedia of physics, v. 6. Springer-Verlag, Berlin. Pp. 551-562.nJohnson, J. A. 1973. Crack initiation in wood plates. Wood Sci. 6(2):151-158.nMijovic, J. S., and J. A. Koutsky, 1979. Effect of wood grain angle on fracture properties and fracture morphology of wood-epoxy joints. Wood Sci. 11(3): 164-168.nMostovoy, S. and E. J. Ripling, 1975. Flaw tolerance of a number of commercial and experimental resins. Adhesion Sci. Technol. 93:513-562 (edited by P. H. Lee, Plenum).nRipling, E. J., S. Mosrovoy, R. L. Patrick. 1964. Measuring fracture toughness of adhesive joints, Mater Res. Stand 4 pp 129-134.nRiver, B. H. 1978. Measurement of shear modulus and shear strength of adhesives. Forest Products Laboratory Communication, Madison, Wisconsin.nRuedy, T. C. 1977. The effect of grain angle orientation on the fracture toughness of wood adhesive systems. M.S. Thesis, Forestry and Forest Products, Virginia Polytechnic Institute and State University.nStrickler, M. D., and R. F. Pellerin, 1973. Rate of loading effect on tensile strength of wood parallel to the grain. For. Prod. J. 23(10):34-36.nWilliams, M. D. 1969. The continuum interpretation for fracture and adhesion. J. Appl. Polym. Sci. 13(1):29-40.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.
