Sökning: "microcracks"

Visar resultat 1 - 5 av 25 avhandlingar innehållade ordet microcracks.

  1. 1. Wave propagation in rock and the influence of discontinuities

    Författare :Andreas Eitzenberger; Charlie Chunlin Li; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : This thesis concerns wave propagation in rock as a tool for determination of rockproperties and as a consequence of activities, such as trains.Using waves as a tool often means that rock properties are determined or the interior of a sample is studied without being damaged. LÄS MER

  3. 2. Synthesis and Characterization of MgA1ON-BN refractories

    Författare :Zuotai Zhang; Seshadri Seetharaman; Kazuhiro Nagata; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MgAlON-BN composites; Mechanical properties; Thermal shock durability; Thermal diffusivity conductivity; Corrosion resistance.; Metallurgical process engineering; Metallurgisk processteknik;

    Sammanfattning : In order to meet the need of metallurgical industry in the world, a new MgAlON-BN composite which can be used for example in special refractory nozzles, tubes and break rings for the continuous casting of steel was studied in the present thesis. The aim was to understand the mechanism of synthesis and their physicochemical properties during the application. LÄS MER

  4. 3. Micromechanics approach to stiffness characterization of woven composites

    Författare :Normunds Jekabsons; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Sammanfattning : Thesis consider the stiffness of woven composites, methods of its calculation and stiffness reduction due to damage accumulation during the service. First, reliable methods for stiffness calculation of undamaged woven composites are considered. There are a large amount of simple approximate methods available in literature. LÄS MER

  5. 4. Deformation and failure of brittle rocks under compression

    Författare :Chunlin Li; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : This thesis describes the deformation and failure of rocks under compression through a micromechanics model and laboratory studies of the Kaiser effect. It comprises an overview and seven appended papers. The deformation model is developed based on the analysis of the behaviour of microcracks. LÄS MER

  7. 5. Oxidation, Creep and Fatigue Synergies in Cast Materials for Exhaust Manifolds

    Författare :Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Stefan Jonsson; Johan Ahlström; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; low-cycle fatigue; fatigue in an inert atmosphere; fatigue in a synthetic diesel exhaust atmosphere; corrosion-fatigue; creep-fatigue; high-temperature corrosion; high-temperature fatigue; synergistic effect; corrosion-fatigue synergy; creep-fatigue synergy; high-temperature alloys; fatigue damage; creep-fatigue damage; corrosion-fatigue damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; precipitation; aging.; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The future development of engines of heavy-duty vehicles towards reduced CO2 emission will increase the exhaust gas temperature and render the exhaust atmosphere more corrosive. The current service material of exhaust gas components - a ferritic ductile cast iron called SiMo51 - will soon meet its upper-temperature limit. LÄS MER