New Shear Strength Test for Solid Wood
Keywords:Shear strength, shear test, wood, wood grain
AbstractA new method for testing material properties has been applied to determine the shear strengths of specimens of Sitka spruce and Douglas-fir. The method permits the realization of pure shear in the critical section of the specimen. Pure shear is not achieved in the current American Society for Testing and Materials (ASTM) shear test. The large strength ranges of wood fibers and the vast differences in strength between earlywood and latewood fibers can still cause significant scatter in the test data, but the effect of combined stresses can be effectively controlled. Because of the special properties of wood, failure always follows the slope of the grain. The new method can only yield shear strength parallel to grain, which is required for engineering design purposes.
American Society for Testing Materials. 1981. Standard methods of testing small clear specimens of timber. ASTM D-143-52. Philadelphia, PA.nArcan, M., Z. Hashin, and A. Voloshin. 1978. A method to produce uniform plane-stress states with applications to fiber-reinforced materials. Exp. Mech.18(4):141-146.nCoker, E. G., and G. P. Coleman. 1935. Photoelastic investigation of shear tests of timber. The Institute of Civil Engineers (England). Selected Engineering Papers. William Cloroes and Sons, Ltd., London and Beccles.nCowin, S. C. 1979. On the strength anisotropy of bone and wood. ASME Trans. J. Appl. Mech.46:832-838.nHerakovich, C. T., and H. W. Bargner, Jr. 1980. Finite element stress analysis of a notched coupon specimen for in-plane shear behavior of composites. Composites11(3):149-154.nJayne, B. A. 1959. Mechanical properties of wood fiber. Tech. Assoc. Pulp and Paper Ind.42(6):461-467.nJayne, B. A. 1960. Some mechanical properties of wood fibers in tension. For. Prod. J.10(6):316-322.nJurf, R. A., and R. B. Pipes. 1982. Interlaminar fracture of composite materials. J. Composite Materials16:386-394.nKollmann, F. F. P., and W. A. Côté, Jr. 1968. Principles of wood science and technology. I. Solid wood. Springer-Verlag, Berlin-Heidelberg.nRadcliffe, B. M., and S. K. Suddarth. 1955. The notched beam shear test for wood. For. Prod. J.5(2):131-135.nRhude, M. J. 1950. A survey of methods for making shear tests of wood. M.S. thesis, Civil Engineering, University of Wisconsin.nVoloshin, A., and M. Arcan. 1980. Failure of unidirectional fiber-reinforced materials—New methodology and results. Exp. Mech.20(8):280-284.n
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.