Sökning: "Multiaxial stress state"

Hittade 5 avhandlingar innehållade orden Multiaxial stress state.

  1. 1. Fundamental models and testing of creep in copper

    Författare :Fangfei Sui; Pavel A. Korzhavyi; Rolf Sandström; Alan Cocks; KTH; []
    Nyckelord :Copper; Creep tests; Multiaxial stress state; Finite element method; Basic modelling; Tertiary creep; Precipitation hardening;

    Sammanfattning : Many sustainable technologies for energy production, for example, generation IV nuclear system, demand the use of materials operating at elevated temperatures for long duration of up to 60 years. Requirements that are even more stringent are found for creep exposed copper canisters for disposal of spent nuclear waste. LÄS MER

  3. 2. Static and fatigue analyses of welded steel structures : some aspects towards lightweight design

    Författare :Mansoor Khurshid; Zuheir Barsoum; Lars-Erik Lindgren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue strength; welded joints; static strength; high strength steel; Farkostteknik; Vehicle and Maritime Engineering; Aerospace Engineering; Flyg- och rymdteknik;

    Sammanfattning : The objectives of this thesis comprise of overcoming the challenges in designing lightweight welded structures such as material selection, choice of fatigue design methods, and increased performance by using improvement techniques. Material selection of welded joints is dependent on the filler and base material strengths. LÄS MER

  4. 3. Transverse failure initiation in polymer composites

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

    Sammanfattning : Transverse failure is one of the most important failure modes in polymer composites. The phenomenon often causes the first deviations from nonlinear laminate behavior. Also, in pressure vessels and pipes, fluid leakage through a path of transverse cracks is often the limiting design criterion. LÄS MER

  5. 4. Probabilistic high cycle fatigue models - volumetric approaches

    Författare :Salar Sadek; Mårten Olsson; Anders Ekberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Fatigue is the most frequent failure mode and must be considered in a mechanical designof actual operating components. The fact that mechanical design is most often linkedwith existence of stress raisers and multiaxial time-varying stresses has in the last decadesincreased the research effort worldwide. LÄS MER

  7. 5. Modelling of cyclic and viscous behaviour of pearlitic steels. Application to tread braked railway wheels

    Författare :Ali Esmaeili; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway wheels; viscoplasticity; tread braking; rolling contact fatigue; full-scale brake rig testing; finite element analysis; plasticity;

    Sammanfattning : Railway wheel and rail materials are subjected to very high stresses and, in some cases, also elevated temperatures. The rolling contact loading results in a multiaxial stress state with a combination of compression and shear. LÄS MER