Sökning: "crack path"

Visar resultat 26 - 30 av 46 avhandlingar innehållade orden crack path.

  1. 26. Numerical modelling of the rock fragmentation process by mechanical tools

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

    Sammanfattning : The rock fragmentation process by mechanical tools is investigated using numerical method. The rock and tool interaction code (R-T2D) is first developed on the basis of the rock failure process analysis (RFPA) model and the finite element analysis (FEA) method. LÄS MER

  3. 27. A study of the fatigue behaviour of laser and hybrid laser welds

    Författare :Md. Minhaj Alam; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Manufacturing Systems Engineering; Produktionsutveckling;

    Sammanfattning : This licentiate thesis focuses on the fatigue cracking behaviour of laser and hybrid laser-MAG welded structures. Beside the welding process and the resulting weld, several topics related to fatigue of welded structures are treated such as; macro and micro surface geometry, weld defects and their influence on fatigue performance of welded structures, fatigue analysis by the nominal and effective notch stress method, fatigue life prediction using LEFM (Linear Elastic Fracture Mechanics), fatigue testing, metallurgical analysis, elastic and elastic-plastic finite element analysis. LÄS MER

  4. 28. Fiber bridging concepts applied to short fiber composites

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

    Sammanfattning : Polymer composite materials are in wide-spread use in the transportation industry. In aerospace industry the use these materials are established while in automotive industry the interest is increasing. LÄS MER

  5. 29. Matrix and interface effects on microcracking in polymer composites

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

    Sammanfattning : An underlying industrial problem for the present work is leakage of pressure vessels. Fluid leakage was confirmed to take place along a path of connected microcracks and delaminations. The thesis is concerned with the micromechanisms for microcracking studied by in-situ optical microscopy of cross-ply laminates. LÄS MER

  7. 30. Confined Compression of Single Particles : Development of a Novel Triaxial Testing Instrument and Particle-Scale Modelling

    Författare :Henrik Jonsson; Göran Frenning; Göran Alderborn; Abderrahim Michrafy; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Powder compaction; Compression; Single particle; Particle mechanics; Powder mechanics; Confined conditions; Triaxial; Apparatus design; Modelling; Galenisk farmaci; Pharmaceutics;

    Sammanfattning : When predicting the performance of a powder compaction process, assessing the behaviour of the particles comprising the powder bed is of central relevance. Currently, however, no experimental methods are available for mimicking the multiaxial loading conditions imposed on the individual particles in a powder bed during compaction, and such analyses are therefore usually performed in silico. LÄS MER