Search for dissertations about: "Short cracks"

Showing result 1 - 5 of 52 swedish dissertations containing the words Short cracks.

  2. 1. Modelling and simulation of short fatigue cracks

    Author : Christina Bjerkén; Materialteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; materialteknik; Materiallära; Material technology; Interface cracks; Dislocations; Short cracks; Local plasticity;

    Abstract : The growth of short fatigue cracks deviates from the behaviour of long fatigue cracks even if subjected to the same nominal driving force. The influence from the microstructure is pronounced, while crack closure effects may not be that important as for longer cracks. READ MORE

  4. 2. Numerical Modelling of Short Fatigue Crack Growth

    Author : Per Hansson; Mekanik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; discrete dislocation; Fatigue; grain boundary; short crack;

    Abstract : Fatigue implies repeated loading and unloading of a structure, and components subjected to fatigue might experience nucleation of cracks, and subsequent crack propagation. This might lead to catastrophic consequences, such as complete failure of a structure. READ MORE

  5. 3. Non-overlapping Germ-grain Models: Characteristics and Material Modelling

    Author : Jenny Andersson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Poisson process; Convex sets; Material fatigue; Voronoi tessellation; Germ-grain process; Pair-correlation function; Mark-correlation function; Short cracks; Volume fraction; Germ-grain process;

    Abstract : We consider three different non--overlapping germ--grain models, two of which are constructed in a similar fashion. These two models are generalisations of Mat\'ern's hard--core models. In both cases we start with a homogeneous Poisson process and use the points as centres of convex sets, grains, of the same shape. READ MORE

  6. 4. Mechanical behaviour of a roller bearing steel : Strength differential effect, low temperature creep and propagation of short cracks

    Author : Irene Linares Arregui; Bo Alfredsson; Nils-Gunnar Ohlson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Fatigue cracks in bearings either initiate from the surface or from an inclusion below the rolling contact surface. Then, short cracks start to propagate. Short crack grow at considerably faster rates than long cracks subjected to a nominally equivalent stress intensity factor range. READ MORE

  7. 5. Life prediction and mechanisms for the initiation and growth of short cracks under fretting fatigue loading

    Author : Alessandro Cadario; Bo Alfredsson; David Nowell; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fretting fatigue; Fretting experiment; Friction evolution; Fatigue crack initiation; Fatigue crack growth; Short crack; Non-destructive testing; Acoustic emission; Potential drop; Shot peening; Stress relaxation; Crack closure; Finite element method; Titanium alloy.; Engineering mechanics; Teknisk mekanik;

    Abstract : Fretting fatigue is a damage process that may arise in engineering applications where small cyclic relative displacements develop inside contacts leading to detrimental effects on the material fatigue properties. Fretting is located in regions not easily accessible, which makes it a dangerous phenomenon. READ MORE