Sökning: "Torsional stress"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden Torsional stress.

  1. 1. Mechanical Pulp. Effects of Pretreatment and Wood Source on Fiber Separation and Pulp Properties

    Författare :Lars Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; torsional stress; pulp properties; chips; impregnation; screw press; SEM; mechanical pulp; sulfonation; shear stress; fracture surface; wood quality; temperature;

    Sammanfattning : The work presented in this thesis concerns the mechanical pulping process and the effects of wood source and pretreatment conditions on the pulp properties. In the first part, the deformation of Norway spruce (Picea abies) wood samples was investigated under shear and torsional loading at different temperatures (20-95°C) and sulfonation conditions. LÄS MER

  3. 2. Effects of temperature and sulfonation on deformation of spruce wood

    Författare :Lars Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sulfonation; deformation; temperature; Scandinavian spruce; shear stress; torsional stress; fracture surface; SEM;

    Sammanfattning : .... LÄS MER

  4. 3. On inelastic local flange buckling

    Författare :Mikael Möller; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik; Steel Structures; Stålbyggnad;

    Sammanfattning : This thesis deals with inelastic local buckling of I-beam flanges made of steel. The main focus is on the theoretical description of the buckling process, and the influence of various parameters, e.g. the plastic modulus, yield plateau, yield stress etc. LÄS MER

  5. 4. Chromatin remodeling and dna topology in transcription and genome stability

    Författare :Jenna Persson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Eukaryotic DNA is wrapped around histone proteins to form nucleosomes, the fundamental repeating unit of chromatin. DNA packaging into chromatin both solves and creates problems. It allows the centimeters, or even meters, of DNA that constitute a eukaryotic genome to fit inside a micrometer-scale cell nucleus. LÄS MER

  7. 5. The effect of inelastic deformation on crack loading

    Författare :Dimosthenis Floros; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; Mixed mode; Configurational mechanics; Gradient plasticity;

    Sammanfattning : Rolling contact fatigue (RCF) cracks in rails are among the most detrimental railway track defects, in relation to reliability and cost. The cracks grow in a mixed mode II & III, which in combination with the rotating stress field in the neighborhood of the crack-tip, large plastic deformations on the rail surface, crack face friction due to the compressive stresses from the wheel load and anisotropic crack growth resistance, add to the complexity related to the study of RCF cracks. LÄS MER