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43 results found
The proposed method of modelling orthotropic solids that have a nonlinear constitutive material relationship affords several advantages. The first advantage is the application of a simple bilinear stress-strain curve to represent the material response on two orthogonal axes as well as in shear,…
Author(s): E.P. Saliklis, T. J. Urbanik, B. Tokyay
Keywords: Stress strain properties, paper, paperboards, mathematical models, algorithms, data
Source: Journal of pulp and paper science. Vol. 29, no. 12 (Dec. 2003): Pages 407-411
Year: 2003
The arrangement of anatomical elements in the cross section of a tree can be characterized, at least to a first approximation, with a cylindrical coordinate system. It seems reasonable that the physical properties of wood in the transverse plane, therefore, would exhibit behaviour that is…
Author(s): John C. Hermanson
Keywords: Elastic analysis, finite element method, mathematical models, wood, physical properties, radial load, tangential load, transverse elastic constants, orthotropic models
Source: Proceedings of the Second International Conference of the European Society for Wood Mechanics : May 25th-28th, 2003, Stockholm, Sweden. Stockholm, Sweden : STFI-Packforst AB, 2003: pages 207-211
Year: 2003
The state of the art among most industry citations of box compression estimation is the equation by McKee developed in 1963. Because of limitations in computing tools at the time the McKee equation was developed, the equation is a simplification, with many constraints, of a more general…
Author(s): Thomas J. Urbanik, Benjamin Frank
Keywords: Box compression, strength, model, bending stiffness, ECT, BCT, buckling, corrugated paperboard, boxes, mathematical models, mathematical optimization, finite element method, bending strength, McKee equation, corrugated fiber containers, compression tests, fiberboard boxes, literature reviews, review article
Source: Wood and fiber science. Vol. 38 no. 3 (2006): pages 399-416.
Year: 2006
The anisotropy of wood complicates solution of heat and mass transfer problems that require analyses be based on fundamental material properties of the wood structure. Most heat transfer models use average thermal properties across either the radial or tangential direction and do not differentiate…
Author(s): John F. Hunt, Hongmei Gu
Keywords: Finite element analysis, transient heat transfer, cellular characteristics, porosity, thermal conductivity, anisotropy, mass transfer, finite element method, heat conduction, softwood, heat flux, heat transmission, thermal properties, wood density, mathematical models
Source: Wood and fiber science. Vol. 38, no. 4 (2006): pages 592-598.
Year: 2006
A fiber model and simulation method are employed to investigate the mechanical response of planar fiber networks subjected to elongational deformation. The simulated responses agree qualitatively with numerous experimental observations. suggesting that such simulation methods may be useful for…
Author(s): Leonard H. Switzer, Daniel J. Klingenberg, C. Tim Scott
Keywords: Paper, mechanical properties, deformations, simulation methods, fibers, papermaking, mathematical models, handsheets, tensile strength, physical properties
Source: Nordic pulp and paper research journal. Vol. 19, no. 4 (2004): p. 434-439.
Year: 2004
This is a mathematical analysis of the stress distribution existing near a hole in a wood or plywood plate subjected to tension, as, for example, near holes in the tension flanges of wood box beams. It is assumed that the strains are small and remain within the proportional limit. In this…
Author(s): C. B. Smith
Keywords: Plywood, strength, mathematical models, analysis, stresses
Source: Report / Forest Products Laboratory (U.S.)-no. 1510. Madison, WI : U.S. Forest Service, Forest Products Laboratory, 1944: 25 pages.
Year: 1944
A thin, solid, circular wood disk, cut from the transverse plane of a tree stem, can be modeled as a cylindrically orthotropic elastic material. It is known that a stress singularity can occur at the center of a cylindrically orthotropic disk subjected to uniform pressure. If a solid cylindrically…
Author(s): Jay A. Johnson, John C. Hermanson, Steven M. Cramer, Charles Amundson
Keywords: Anisotropic materials, elastic analysis, mathematical models, stress analysis, wood products, pressures
Source: Journal of engineering mechanics. (Feb. 2005): pages 153-160.
Year: 2005
These proceedings papers and poster summaries discuss the influence of air pollution on relationships; interactions of producers, consumers, and decomposers under pollutant terrestrial and related aquatic ecosystems. They describe single species-single pollutant stress; and the use of ecological…
Author(s): Paul R. Miller
Keywords: Air pollution injury, acidic precipitation, pollutant stress, terrestrial habitats, species-pollutant relationship, mathematical models
Source: General Technical Report PSW-43, Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 256 p
Year: 1980
To comply with the U.S. Environmental Protection Agency's "Cluster Rule," most U.S. mills have switched from the use of chlorine to chlorine dioxide as the oxidant in the first stage of bleaching. This process change has a downside. it increases the formation of mineral scale in bleach plants.…
Author(s): Alan Rudie, Peter Hart
Keywords: Incrustations, pulp mills, bleaching, oxalic acid, calcium oxalate, mathematical models, pulp and paper processes, scale, digesters, chemical precipitation
Source: Solutions : for people, processes and paper. (June 2005): Pages 45-46
Year: 2005
One of the more common areas of mineral scale formation in bleach plants is on washer face wires and the extraction rings of diffusion washers. Whereas most scale problems can be understood as a mixing of two streams that increase the concentrations of anions and cations and exceed a solubility…
Author(s): Alan Rudie, Peter Hart
Keywords: Incrustations, wood pulp, washing, calcium, pulp mills, bleaching, finite element method, cations, ion exchange, anions, mathematical models, pulp and paper processes, washing, chemical precipitation, scale
Source: Proceedings of the 2004 TAPPI fall technical conference : October 31-November 3, 2004, Atlanta, GA. Atlanta, GA : TAPPI Press, 2004: [13] pages
Year: 2004