Sökning: "Byggteknik"

Visar resultat 1 - 5 av 61 avhandlingar innehållade ordet Byggteknik.

  1. 1. Experimental characterization and numerical modeling of compression perpendicular to the grain in wood and cross-laminated timber

    Författare :Shaheda T. Akter; Thomas K. Bader; Erik Serrano; Jan Oscarsson; Reinhard Brandner; Linnéuniversitetet; []
    Nyckelord :rolling shear; biaxial testing; stress combination; RT-plane; moisture influence; rolling shear creep; digital image correlation; strain field; CLT connection; rotational stiffness; rullskjuvning; biaxiell undersökning; spänningskombination; RT-plan; fuktpåverkan; krypning vid rullskjuving; digital bildkorrelation; töjningsfält; KLTanslutning; rotationsstyvhet; Byggteknik; Civil engineering;

    Sammanfattning : Compression perpendicular to the grain (CPG) of wood is a typical loading situation in timber structures. It has been an extensively studied research topic for decades, due to the highly ductile behavior of wood under such loading, the large variations in mechanical properties, and the relevance of these properties in structural design. LÄS MER

  2. 2. 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

  3. 3. 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

  4. 4. Pith location and annual ring detection for modelling of knots and fibre orientation in structural timber : A Deep-Learning-Based Approach

    Författare :Tadios Habite; Anders Olsson; Osama Abdeljaber; Jan Oscarsson; Welf Löwe; Julie Cool; Linnéuniversitetet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Sawn timber; Pith location; Deep learning; Artificial neural networks; Convolutional neural network; Conditional generative adversarial network; Knot detection; Knot modelling; Knot reconstruction; Fibre orientation; Annual ring profile; Byggteknik; Civil engineering;

    Sammanfattning : Detection of pith, annual rings and knots in relation to timber board cross-sections is relevant for many purposes, such as for modelling of sawn timber and for real-time assessment of strength, stiffness and shape stability of wood materials. However, the methods that are available and implemented in optical scanners today do not always meet customer accuracy and/or speed requirements. LÄS MER

  5. 5. 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