Sökning: "micro crack"

Visar resultat 1 - 5 av 46 avhandlingar innehållade orden micro crack.

  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

  2. 2. The role of microstructure for crack propagation in cortical bone

    Författare :Anna Gustafsson; Avdelningen för Biomedicinsk teknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Crack deflection; Interface; Mechanical testing; Micro-CT; Osteon; Porosity; XFEM;

    Sammanfattning : Healthy cortical bone tissue is both tough and strong and has a unique ability to resist fracture. One reason is the hierarchical structure of the tissue where toughening mechanisms at all length scales act to slow down or stop a propagating crack. LÄS MER

  3. 3. Predicting shear type crack initiation and growth in concrete with non-linear finite element method

    Författare :Richard Malm; Håkan Sundquist; Anders Ansell; Kent Gylltoft; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-linear finte element analysis; concrete; crack width; crack propagation; shear; Building engineering; Byggnadsteknik;

    Sammanfattning :   In this thesis, the possibility to numerically describing the behaviour that signifies shear type cracking in concrete is studied. Different means for describing cracking are evaluated where both methods proposed in design codes based on experiments and advanced finite element analyses with a non-linear material description are evaluated. LÄS MER

  4. 4. On the deformation behavior and cracking of ductile iron; effect of microstructure

    Författare :Keivan Amiri Kasvayee; Anders E.W. Jarfors; Jens Bergström; Högskolan i Jönköping; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spherical graphite iron; component casting; high silicon ductile iron; digital image correlation DIC ; in-situ tensile testing; in-situ cyclic testing; DIC pattern generation; pit etching; micro-scale deformation; micro-crack; finite element analysis FEA ; focused ion beam FIB milling; segjärn; komponentgjutning; högkisellegerat segjärn; digital image correlation DIC ; insitu dragprovning; in-situ cyklisk provning; DIC-mönstergenerering; grop-etsning; mikroskalig deformation; mikrosprickor; finite element analys FEA ; fokuserad jonstråle FIB avverkning;

    Sammanfattning : This thesis focuses on the effect of microstructural variation on the mechanical properties and deformation behavior of ductile iron. To research and determine these effects, two grades of ductile iron, (i) GJS-500-7 and (ii) high silicon GJS-500-14, were cast in a geometry containing several plates with different section thicknesses in order to produce microstructural variation. LÄS MER

  5. 5. Modelling of large deformation crack propagation based on the extended finite element method

    Författare :Martin Fagerström; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack propagation; strong discontinuities; material crack driving force; FEM; cohesive zone;

    Sammanfattning : This thesis is concerned with the finite element modelling of large deformation crack propagation, based on the extended finite element methodology. The benefit from this approach is the possibility of locally enriching the finite element space, i.e. to add a priori knowledge about the local behaviour of the solution in order to improve accuracy. LÄS MER