Sökning: "fatigue initiation"

Visar resultat 1 - 5 av 113 avhandlingar innehållade orden fatigue initiation.

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. Fatigue life prediction of additively manufactured ductile nickel-based superalloys : Constitutive and crack initiation modelling

   Författare :Thomas Lindström; Daniel Leidermark; Kjell Simonsson; Robert Eriksson; Magnus Ekh; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive manufacturing; Low-cycle fatigue; Thermomechanical fatigue; Constitutive modelling; Anisotropy;

   Sammanfattning : This dissertation was produced at the Division of Solid Mechanics at Linköping University, and is the final result of a project that included mechanical testing and modelling of an additively manufactured ductile nickel-based superalloy.The main objective of the work presented in this thesis was to investigate and model the cyclic behaviour and the fatigue life behaviour of an additively manufactured ductile nickel-based superalloy, with emphasis on modelling the stabilised material behaviour, by which fatigue life predictions can be based upon. LÄS MER

5. 4. Crack Initiation in Nodular cast Iron

   Författare :Marie Mörtsell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nodualr cast iron; fatigue; mechanical properties; crack initiation;

   Sammanfattning : .... LÄS MER

7. 5. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

   Författare :Jonas Ringsberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

   Sammanfattning : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. LÄS MER