Sökning: "Byggteknik"

Visar resultat 1 - 5 av 55 avhandlingar innehållade ordet Byggteknik.

  1. 1. Modelling and strength grading of structural timber and glulam lamellae on the basis of optical scanning and dynamic excitation

    Författare :Andreas Briggert; Anders Olsson; Jan Oscarsson; Mikael Perstorper; Linnéuniversitetet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre direction; finger joint; machine strength grading; knots; tracheid effect; Norway spruce; Byggteknik; Civil engineering;

    Sammanfattning : Machine strength grading of sawn timber is a sawmill process in which density, modulus of elasticity (MOE) and bending or tensile strength are predicted such that the timber can be assigned to strength classes. The predictions of these properties are performed using one or several so-called indicating properties (IPs), which represent a board property, or combination of board properties, measured non-destructively. LÄS MER

  2. 2. Moisture-induced stress and distortion of wood : A numerical and experimental study of wood's drying and long-term behaviour

    Författare :Sara Florisson; Sigurdur Ormarsson; Johan Vessby; Kent Persson; Linnéuniversitetet; []
    Nyckelord :AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; analytical method; calibration; controlled climate; creep; distortion; experimental methodology; FEM; fibre orientation; mechano-sorption; moisture transport; natural climate; Norway spruce; numerical model; three-dimensional; timber beam; validation; wood; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : With the current advances made in three-dimensional modelling of wood, it is possible to provide an overall picture of moisture flow, and moisture-induced stress and deformations, whereas previously, experiments only provided local measurements. The main aim of the doctoral thesis is to investigate the possibilities of the developed three-dimensional numerical model to predict the behaviour of wood when simultaneously exposed to a mechanical load and a particular climate. LÄS MER

  3. 3. A Finite Element Study of the Shape Stability of Sawn Timber Subjected to Moisture Variations

    Författare :Sigurdur Ormarsson; Hans Petersson; Ola Dahlblom; Lund University; []
    Nyckelord :simulation; deformation; wood; moisture; finite element method; Byggteknik; Civil engineering;

    Sammanfattning : Shape instability in timber products exposed to moisture variation is a serious problem since it can make wood products unsuitable for construction purposes. In this thesis the finite element method has been used to simulate deformations during the drying process.….…. LÄS MER

  4. 4. Nonlinear modeling of reinforced dowel joints in timber structures : a combined experimental-numerical study

    Författare :Michael Schweigler; Josef Eberhardsteiner; Thomas K. Bader; Thierry Descamps; Vienna University of Technology; []
    Nyckelord :AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; Technology byts ev till Engineering ; Teknik; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Steel dowels are indispensable elements for the design of joints in modern timber structures. Dowels are broadly used because of their flexibility in design and easy assembling on-site, as well as due to their advantageous mechanical behavior. LÄS MER

  5. 5. Strength grading of structural timber and EWP laminations of Norway spruce - Development potentials and industrial applications

    Författare :Jan Oscarsson; Anders Olsson; Marie Johansson; Hans Joachim Blass; SE-351 96 Växjö Videum Science Park SP Technical Research Institute of Sweden SP Wood Technology; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fibre angle; grain angle; knots; laser scanning; machine strength grading; modulus of elasticity; side boards; strain; structural timber; wet gluing; wood; Byggteknik; Civil engineering;

    Sammanfattning : Machine strength grading of structural timber is a sawmill process by which considerable value is added to sawn products. The principle of such grading is that the strength of a timber member is predicted on the basis of a so called indicating property (IP) which, in general, represents an averaged value of the modulus of elasticity (MOE) measured over a board length of about one meter or more. LÄS MER