Sökning: "Ratcheting"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet Ratcheting.

  1. 1. On the modeling of large ratcheting strains and anisotropy in pearlitic steel

    Författare :Göran Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large strains; Plasticity; Anisotropy; Ratcheting; Kinematic hardening;

    Sammanfattning : Thermodynamically consistent constitutive material models for describing the large strain response of polycrystalline metals are proposed. Emphasis is put on the multiaxial ratcheting under cyclic loading and the evolution of anisotropy in pearlitic steel. LÄS MER

  3. 2. Constitutive Modeling of Large Ratcheting Strains in Carbon Steel

    Författare :Göran Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : A thermodynamically consistent constitutive materialmodel for describing the large strain response of polycrystallinemetals during cyclic loading is proposed. In particular, it isproposed to model experimentally observed large ratcheting strainsin rail steel by the classical Armstrong-Frederick evolution ruleand several back-stresses. LÄS MER

  4. 3. On the Simulation of Progressive Deformation in Nuclear Piping

    Författare :Andreas Gustafsson; Jan Granlund; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel Structures; Stålbyggnad;

    Sammanfattning : In this thesis the performance of different constitutive models in ratchet simulation is investigated. Ratcheting is accumulated plastic strains which may occur when a structure is subjected to a constant load in combination with cyclic loading. LÄS MER

  5. 4. Analysis of rail breaks and insulated joint deterioration

    Författare :Johan Sandström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rail breaks; Heavy Haul; Insulated joints; Wheel flats; Railway mechanics; Material fatigue;

    Sammanfattning : The thesis deals with fatigue related issues in the field of railway mechanics. In particular rail breaks and deterioration of insulating joints are investigated. The study is largely motivated by plans to increase allowed axle loads in Sweden. 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