Sökning: "Fracture wood"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden Fracture wood.

  1. 1. Multiphase continuum modeling of wood : A hybrid mixture theory approach

    Författare :Winston Mmari; Björn Johannesson; Lynn Schreyer; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Moisture transport; Coupled heat and moisture; Over-hygroscopic; Hybrid mixture theory; Mixture theory; Swelling; Hygro-mechanical; Non-linear elasticity; Large deformation; Phase field crack model; Anisotropic cracking; FEM; Numerical model; Norway spruce; Wood; Porous media; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Wood has been used as a construction material for a very long time. The development of efficient industrial production processes of wood has expanded the use of the material with the introduction of new products, such as engineered wood products. LÄS MER

  3. 2. Fracture processes in wood chipping

    Författare :Lisbeth Hellström; Per Gradin; Torbjörn Carlberg; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wood chipping; chip formation; digital speckle photography; friction; fracture processes; analytical model; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : In both the chemical and mechanical pulping process, the logs are cut into wood chips by a disc chipper before fibre separation. To make the wood chipping process more efficient, one have to investigate in detail the coupling between theprocess parameters and the quality of the chips. LÄS MER

  4. 3. A numerical and experimental study of initial defibration of wood

    Författare :Stefan Holmberg; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite element simulations; fracture; deformation; fibre; defibration; wood; Building construction; Byggnadsteknik;

    Sammanfattning : A major drawback of the defibration or refining process in manufacturing pulp is that of its large energy requirements. If the mechanics of the process were better understood, large amounts of energy could probably be saved. The initial defibration seems to be crucial for both the quality of the pulp and the total consumption of energy. LÄS MER

  5. 4. On the wood chipping process : a study on basic mechanisms in order to optimize chip properties for pulping

    Författare :Lisbeth Hellström; Torbjörn Carlberg; Per Engstrand; Sören Östlund; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wood chipping; Chip formation; Digital Speckle Photography; Friction; Fracture Processes; Analytical model; Laboratory Wood Chipper; Force Measurement; Vibration Synthesis; Energy Efficiency; Chip Damage; TMP; CTMP; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : In both the chemical and mechanical pulping process, the logs are cut into wood chips by a disc chipper before fibre separation. To make the wood chipping process more efficient, one have to investigate in detail the coupling between process parameters and the quality of the chips. LÄS MER

  7. 5. Strength grading of structural timber and EWP laminations of Norway spruce : Development potentials

    Författare :Jan Oscarsson; Anders Olsson; Marie Johansson; Mikael Perstorper; SP Sveriges Tekniska Forskningsinstitut; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bending strength; fibre angle; grain angle; knots; laser scanning; machine strength grading; modulus of elasticity; strain measurement; structural timber; tensile strength; wood; böjhållfasthet; draghållfasthet; elasticitetsmodul; fibervinkel; konstruktionsvirke; kvistar; laserskanning; maskinell hållfasthetssortering; trä; töjningsmätning; Byggteknik; Civil engineering;

    Sammanfattning : Strength grading of structural timber is a process by which value is added to sawn products. It is to the greater part carried out using machine grading based on statistical relationships between so called indicating properties and bending strength. LÄS MER