Fabrication and Design of Glued Laminated Wood Structural MembersU.S. Department of Agriculture, 1954 - 220 páginas |
Términos y frases comunes
1-foot lengths 17 LAMINATIONS adjacent laminations applied average basic stress bending butt joints casein glue cauls columns compression compression members computed cross grain cross section curing chamber curvature curved members dielectric heating Douglas-fir durable edge gluing edge joints effect end joints factor fiber glue joints glue line glued laminated gluing pressure grade heating inches intermediate-temperature-setting knot sizes laminated assembly laminated beams laminated construction laminated members laminated wood lamination thickness load lumber material melamine melamine resins modulus of elasticity modulus of rupture moisture content moment of inertia number of laminations outer laminations percent permit phenol-resorcinol piece plain scarf joint proportional limit resin glues resorcinol retaining clamps shear shear strength shown in figure Sitka spruce southern yellow pine spacing species specimens strength ratio structural sum of knot surfaces tension tests timbers tions urea resins urea-resin glues usually values of IK/IG white oak width
Pasajes populares
Página 144 - ... a cross-bonded assembly made of layers of veneer or veneer in combination with a lumber core or plies joined with an adhesive. Two types of plywood are recognized, namely (1) veneer plywood and (2) lumber core plywood.
Página 144 - The term has no reference to the actual hardness of the wood. Angiosperms is the botanical name for hardwoods.
Página 143 - Encased knot. A knot whose rings of annual growth are not intergrown with those of the surrounding wood. Intergrown, knot. A knot whose rings of annual growth are completely intergrown with those of the surrounding wood.
Página 54 - Where pieces of wood are coated and exposed freely to the air, a much more rapid change in consistency of the glue occurs than where the pieces are laid together as soon as the spreading has been done. The condition of free exposure is conveniently referred to as "open assembly" and the other as "closed assembly.
Página 143 - The botanical group of trees that have needle or scalelike leaves and are evergreen for the most part, cypress, larch, and tamarack being exceptions. The term has no reference to the actual hardness of the wood. Softwoods are often referred to as conifers, and botanically they are called gymnosperms.
Página 130 - ... factor can be taken for short-time than for long-time loading. A convenient way to do this is to use the increases of Fig. 5 for long-column loads calculated with a reduction factor of 3 from the modulus of elasticity values. 7.2.4 Wood under continuing load takes on a deformation known as plastic flow, usually very slow but persistent over long periods of time. Deflection of this nature occurring in timbers acting as beams is sometimes known as "set
Página 145 - Tangential: Strictly, coincident with a tangent at the circumference of a tree or log, or parallel to such a tangent. In practice, however, it often means roughly coincident with a growth ring. Texture: A term often used interchangeably with grain.
Página 145 - D-7 * summerwood— the portion of the annual growth ring that is formed after the springwood formation has ceased. It is usually more dense and stronger mechanically than springwood.
Página 143 - Pieces (nominal dimensions 2 to 4 in. in thickness by 4 in. and wider) of rectangular cross section graded with respect to their strength in bending when loaded either on the narrow face as joist or on the wide face as plank.
Página 1 - glued laminated construction," as applied to structural members, refers to material glued up from smaller pieces of wood, either in straight or curved form, with the grain of all the laminations essentially parallel to the length of the member. It is thus basically different from plywood, in which the grain direction of adjacent plies is usually at right angles. The...