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Showing result 1 - 5 of 87 swedish dissertations matching the above criteria.

2. 1. Oxidation, Creep and Fatigue Synergies in Cast Materials for Exhaust Manifolds

   Author : Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Stefan Jonsson; Johan Ahlström; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

   Author : Jonas Ringsberg; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Crack Initiation in Nodular cast Iron

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

   Abstract : .... READ MORE

6. 4. Fatigue of Spot Welded Joints: Experiments and Life Predictions

   Author : Hans-Fredrik Henrysson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; crack propagation; crack initiation; finite element method; damage accumulation; variable amplitude; fracture mechanics; fatigue; spot welds;

   Abstract : Methods to assess the fatigue strength of spot welds in built-up structures are used on a daily basis in the automotive industry. Efficient and reliable numerical methods make it possible to achieve designs with low weight, low manufacturing costs and good durability within short development cycles, since the number of prototypes built can be reduced. READ MORE

7. 5. Contact fatigue and crack propagation studies of sintered PM steel

   Author : Anders Holmberg; Åsa Kassman Rudolphi; Urban Wiklund; Johan Ahlström; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tribology; PM steel; Fatigue; Crack Initiation; Crack Propagation; Material Analysis; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Abstract : Gears made of PM steel are of interest for the automotive industry because from the press/sinter route, complex geometries can be produced to near net shape with only a few processing steps while keeping the material and energy usage at a minimum. However, the PM steels of today have significant performance limitations caused by the inherent porosity which impairs the mechanical properties by acting as stress raisers in the material. READ MORE