Sökning: "crack closure"

Visar resultat 1 - 5 av 39 avhandlingar innehållade orden crack closure.

  1. 1. High Strain Fatigue Crack Growth and Crack Closure

    Författare :Michael Andersson; Materialteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; materialteknik; Materiallära; Material technology; crack closure; high strain fatigue; crack grotwh;

    Sammanfattning : Understanding of the growth of fatigue cracks is of utmost importance since such growth often has a profound influence on the life of components subjected to cyclic loading. Thus, reliable fatigue life models enable a more efficient use of materials and improve the performance and efficiency in many applications. LÄS MER

  3. 2. Modelling of TMF Crack Growth in Polycrystalline Gas Turbine Alloys : Accounting for Crack Closure Effects

    Författare :Jordi Loureiro-Homs; Kjell Simonsson; Robert Eriksson; Daniel Leidermark; Tomas Månsson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The main objective of the work presented in this Licentiate of Engineering thesis is to investigate and model the fatigue crack propagation behaviour of the nickel-based superalloy Inconel 792, with special attention to the industrial lifing of high-temperature components. In-phase (IP) crack propagation tests have been performed at different temperatures and loading regimes, including extended hold times. LÄS MER

  4. 3. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

    Författare :Jonas Ringsberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

    Sammanfattning : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. LÄS MER

  5. 4. Fatigue of Spot Welded Joints: Experiments and Life Predictions

    Författare :Hans-Fredrik Henrysson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; crack propagation; crack initiation; finite element method; damage accumulation; variable amplitude; fracture mechanics; fatigue; spot welds;

    Sammanfattning : Methods to assess the fatigue strength of spot welds in built-up structures are used on a daily basis in the automotive industry. Efficient and reliable numerical methods make it possible to achieve designs with low weight, low manufacturing costs and good durability within short development cycles, since the number of prototypes built can be reduced. LÄS MER

  7. 5. Thermo-mechanical Fatigue Crack Propagation in Inconel 718

    Författare :Lars Jacobsson; Materialteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; image analysis; potential drop; in-situ scanning elecron microscopy; crack propagation experiments; Thermo-mechanical fatigue; Inconel 718;

    Sammanfattning : Thermo-mechanical fatigue crack propagation in Inconel 718 has been studied with different methods. In-situ observations with a scanning electron microscope (SEM) were performed, the crack propagation process was followed cycle by cycle and the influences from load, temperature, and microstructure on the crack growth were analyzed. LÄS MER