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Visar resultat 1 - 5 av 16 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Elastic-Plastic Fracture Mechanics and RCF in Rails

    Författare :Johan Tillberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RCF; elastic-plastic fracture mechanics; Material-forces; Multiple crack interaction;

    Sammanfattning : This thesis concerns issues regarding the modeling and numerical simulation of singularcracks and their propagation in the context of Rolling Contact Fatigue (RCF) in rails.Typically, such cracks are associated with squats and head-checks in the rail head. LÄS MER

  3. 2. Elastic-plastic fracture mechanics - Application to rolling contact fatigue in rails

    Författare :Johan Tillberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FEM; rolling contact fatigue; railway mechanics; Elastic-plastic fracture mechanics; material forces;

    Sammanfattning : Railway structures represent complex mechanical problems involving wave propagation, plastic deformations and material degradation. The wheel-rail contact loads subject the material to repeated cycles of complex stress states resulting in rolling contact fatigue (RCF). LÄS MER

  4. 3. Numerical models of ductile crack growth

    Författare :Annika Trädegård; KTH; []
    Nyckelord :solid mechanics; nonlinear fracture mechanics; elastic-plastic fracture; finite element method; remeshing; constraint; two-parameter characterisation; stable ductile crack growth; cleavage; weibull stress; void growth;

    Sammanfattning : .... LÄS MER

  5. 4. High-Temperature Durability Prediction of Ferritic-Martensitic Steel

    Författare :Ahmed Azeez; Robert Eriksson; Kjell Simonsson; Daniel Leidermark; Christer Persson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ferritic-martensitic steel; Low cycle fatigue; Thermomechanical fatigue; Crack propagation; Fracture mechanics; Finite element modelling;

    Sammanfattning : Materials used for high-temperature steam turbine sections are generally subjected to harsh environments with temperatures up to 625 °C. The superior creep resistance of 9–12 % Cr ferritic-martensitic steels makes them desirable for those critical steam turbine components. LÄS MER

  7. 5. On structural integrity with emphasis on rate effects of fracture toughness

    Författare :Mikael Lorentzon; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : This thesis is concerned with structural integrity from a fracture mechanics point of view. The emphasis in this work is on rate effects of fracture toughness but all investigations deal with phenomena or problems within the frame work of non-linear fracture mechanics. LÄS MER