Sökning: "fibervinkel"

Hittade 4 avhandlingar innehållade ordet fibervinkel.

  1. 1. Electromagnetic Modelling for the Estimation of Wood Parameters

    Författare :Therese Sjödén; Sven Nordebo; Börje Nilsson; Andreas Fhager; Växjö universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cramér Rao bound; electromagnetic modelling; estimation; grain angle; microwave; wood properties.; Cramér Rao-gräns; elektromagnetisk modellering; estimering; fibervinkel; mikrovågor; träegenskaper.; Engineering physics; Teknisk fysik; Physics; Fysik;

    Sammanfattning : Spiral grain in trees causes trouble to the wood industry, since boards sawn from trees with large grain angle have severe problems with form stability. Measurements of the grain angle under bark enable the optimisation of the refining process. LÄS MER

  3. 2. Sensitivity Analysis and Material Parameter Estimation using Electromagnetic Modelling

    Författare :Therese Sjödén; Sven Nordebo; Börje Nilsson; Margaret Cheney; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sensitivity analysis; material parameter; Fisher information; Cramér-Rao bound; electromagnetic modelling; grain angle; wood; electrical impedance tomography; inverse problems; känslighetsanalys; estimering; materialparameter; Fisher- information; Cramér-Rao-gränsen; elektromagnetisk modellering; fibervinkel; trä; elektrisk impedanstomografi; inversa problem; Waves; Signals and Systems; Vågor; signaler och system;

    Sammanfattning : Estimating parameters is the problem of finding their values from measurements and modelling. Parameters describe properties of a system; material, for instance, are defined by mechanical, electrical, and chemical parameters. Fisher information is an information measure, giving information about how changes in the parameter effect the estimation. LÄS MER

  4. 3. Local variation in bending stiffness in structural timber of Norway spruce : for the purpose of strength grading

    Författare :Min Hu; Marie Johansson; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; digital image correlation; fibre angle; high resolution; laser scanning; local stiffness; MOE profile; mode shape curvature; strain field; strength grading; structural timber; tracheid effect; Digital image correlation; fibervinkel; laserskanning; lokal styvhet; MOE-profil; töjningsfält; hållfasthetssortering; konstruktionsvirke; trakeideffekt; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Most strength grading machines on the European market use an averagemodulus of elasticity (MOE), estimated on a relatively large distance along awood member, as the indicating property (IP) to bending strength. Theaccuracy of such grading machines in terms of coefficient of determination israther low at R2 ≈ 0.5. LÄS MER

  5. 4. 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