Influence of juvenile wood content on shear parallel, compression, and tension transverse to grain strength and mode I fracture toughness for loblolly pine

Abstract

To satisfy the increased demand for forest products, much of future timber supply is expected to be from improved trees grown on managed plantations. This fast growth resource will tend to be harvested in short-age rotations and will contain higher proportions of juvenile wood than those of current harvests. In anticipation of this resource, definitive information is needed about the influence of juvenile wood on lumber properties so that grading rules or the associated allowable design stresses can be modified as needed. Most information developed to date has concentrated on ultimate tensile stress, modulus of rupture, and modulus of elasticity. This paper reports test results for shear stress parallel-to-grain, compression and tension-stress perpendicular-to-grain, and mode I fracture toughness for various percentages of juvenile wood content and ring orientations

Citation

Kretschmann, David E. 2008. Influence of juvenile wood content on shear parallel, compression, and tension transverse to grain strength and mode I fracture toughness for loblolly pine. Research Paper FPL-RP-647. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 27 p.