Sökning: "High Cycle Fatigue"

Visar resultat 1 - 5 av 118 avhandlingar innehållade orden High Cycle Fatigue.

1. 1. 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

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

   Författare :Vitaliy Kazymyrovych; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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. 3. 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. 4. Very high cycle fatigue of tool steels

   Författare :Vitaliy Kazymyrovych; Jens Bergström; Arne Melander; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fatigue; crack growth; ultrasonic testing; tool steels; inclusions; Materialteknik; Materials Engineering;

   Sammanfattning : An increasing number of engineering components are expected to have fatigue life in the range of 107 - 1010 load cycles. Some examples of such components are found in airplanes, automobiles and high speed trains. LÄS MER

7. 5. High-Temperature Corrosion-Fatigue of Cast Alloys for Exhaust Manifolds

   Författare :Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Johan Ahlström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High temperature; corrosion fatigue; low-cycle fatigue; cast alloys; high-temperature oxidation; intermetallic phase; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : The introduction of gas-driven Otto engine and the corresponding usage of bio-fuels in heavy-duty engines will render the exhaust atmosphere more corrosive and bring a higher working temperature to exhaust manifolds. The current service material, a ferritic ductile cast iron called SiMo51, will soon meet its upper temperature limit set by the ferrite-austenite transformation at 860ºC. LÄS MER