Sökning: "Fatigue strength"

Visar resultat 1 - 5 av 201 avhandlingar innehållade orden Fatigue strength.

  1. 1. Fatigue of steel bridges : New structural details and the implementation of high strength steel

    Författare :Oskar Skoglund; John Leander; Raid Karoumi; Alain Nussbaumer; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high strength steel; fatigue; steel bridges; steel and concrete composite bridges; new structural details; linear elastic fracture mechanics; effective notch stress method; nominal stress method; Structural Engineering and Bridges; Bro- och stålbyggnad;

    Sammanfattning : The use of high strength steel has the potential to reduce the amount of steel used in bridge structures and thereby facilitate a more sustainable construction. The amount of steel and what steel grade that can be used in bridge structures and other cyclic loaded structures are often limited by a material degradation process called fatigue. LÄS MER

  2. 2. Fatigue strength of engineering materials : the influence of environment and porosity

    Författare :Jan Linder; Bengt Lindberg; Lennart Josefsson; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stainless steel; cast aluminium; hardened steels; fatigue; corrosion; crack propagation; spot weld; porosity; Other materials science; Övrig teknisk materialvetenskap;

    Sammanfattning : The objective of this work was to use LEFM in order to assess the detrimental influence of surrounding chloride-containing environments for stainless steels, hardened steel as well as for a cast aluminium alloy. An additional aim was also to use LEFM to assess the influence of porosity on the fatigue properties for different commercial cast aluminium alloys and manufacturing methods. LÄS MER

  3. 3. Very high cycle fatigue of high performance steels

    Författare :Vitaliy Kazymyrovych; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; fatigue; tool steels; ultrasonic testing; fatigue life; crack growth rate; fatigue mechanisms; Materialteknik; Materials Engineering;

    Sammanfattning : Many engineering components reach a finite fatigue life well above 109 load cycles. Some examples of such components are found in airplanes, automobiles or high speed trains. For some materials the fatigue failures have lately been found to occur well after 107 load cycles, namely in the Very High Cycle Fatigue (VHCF) range. LÄS MER

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

    Författare :Mansoor Khurshid; Zuheir Barsoum; Lars-Erik Lindgren; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

  5. 5. 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 :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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