Sökning: "crack initiation"

Visar resultat 21 - 25 av 147 avhandlingar innehållade orden crack initiation.

  1. 21. Experiments and modelling of fracture initiation at impact

    Författare :Ola Wall; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Viscoplasticity; Mechanical engineering; Ductile; Brittle; Dynamic; Fracture; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Material technology; Materiallära; materialteknik;

    Sammanfattning : The thesis addresses different questions, each necessary in the understanding of dynamic fracture initiation and crack propagation in steel. Emphasis lays on dynamic crack propagation experiments performed in the ductile to brittle transition region and possible conclusions, that can be drawn from them. LÄS MER

  3. 22. Damage and defects in railway materials: influence of mechanical and thermal damage on crack initiation and propagation

    Författare :Casey Jessop; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : With rising societal concern for the environment, railways offer travelers a sustainable alternative to other forms of fossil-fueled transportation. In order to be competitive with airlines, for example, the railway industry must provide safe, efficient, and affordable service. LÄS MER

  4. 23. Very high cycle fatigue of automotive steels : Testing and computation at 20 kHz

    Författare :Mohamed Sadek; Jens Bergström; Nils Hallbäck; Ulrich Krupp; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Very high cycle fatigue; ultrasonic fatigue testing; automotive steels; fatigue strength; stress intensity computation; crack growth; Materialteknik; Materials Engineering;

    Sammanfattning : Mechanical fatigue failure occurs in components subjected to cyclic loading. A crack initiates at critical regions in the component and propagates during repeated loading. The expected fatigue life depends on the level, type and frequency of the loading. LÄS MER

  5. 24. High-Temperature Durability Prediction of Ferritic-Martensitic Steel

    Författare :Ahmed Azeez; Robert Eriksson; Kjell Simonsson; Daniel Leidermark; Christer Persson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ferritic-martensitic steel; Low cycle fatigue; Thermomechanical fatigue; Crack propagation; Fracture mechanics; Finite element modelling;

    Sammanfattning : Materials used for high-temperature steam turbine sections are generally subjected to harsh environments with temperatures up to 625 °C. The superior creep resistance of 9–12 % Cr ferritic-martensitic steels makes them desirable for those critical steam turbine components. LÄS MER

  7. 25. Dynamic Modelling and Vibration Analysis for Gear Tooth Crack Detection

    Författare :Omar D. Mohammed; Robert Randall; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance Engineering;

    Sammanfattning : The aim of applying vibration-based condition monitoring in gear systems is to detect the initiation and development of degradation before the occurrence of failure. Eventually, degradation will result in a malfunction of the gearing system, which will affect the availability of the whole system. LÄS MER