Search for dissertations about: "Interface cracks"

Showing result 1 - 5 of 71 swedish dissertations containing the words Interface 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. Nonlinear Interaction Between Ultrasonic Waves and Cracks and Interfaces

    Author : Milan Poznic; Leif Kari; Bruce Drinkwater; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic waves; crack; modulation; rough interface; partially closed; surface-breaking; fluid-filled; Acoustics; Akustik;

    Abstract : The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. READ MORE

  5. 3. Life Prediction and Mechanical Behavior of Thermal Barrier Coatings

    Author : Yan Liu; Materialteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stress intensity factors; Macro-cracks; Micro-cracks; Mechanical behaviour; Thermal barrier coatings; Life prediction; Material technology; Materiallära; materialteknik;

    Abstract : Delamination and spallation of thermal barrier coating (TBC) systems, used in hot parts of gas turbines, have been studied with respect to thermal fatigue. TBCs with and without pre-existing cracks were investigated. Thermal shock tests were performed until coating spallation. READ MORE

  6. 4. The role of microstructure for crack propagation in cortical bone

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

    Abstract : 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. READ MORE

  7. 5. Elastic Wave Propagation in Anisotropic Media. Application to Ultrasonic NDT

    Author : A. Jonas Niklasson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; layered media; cylinders; cracks; integral equations; scattering; nondestructive testing; elastic waves; ultrasonics; transducers; anisotropy;

    Abstract : The subject of this thesis is elastic wave propagation in anisotropic materials with application to ultrasonic nondestructive testing (NDT). The first part of the thesis is concerned with modeling of ultrasonic transducers and wave propagation in anisotropic materials in general. First, a scalar 2-D case is considered. READ MORE