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Visar resultat 1 - 5 av 26 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Crystal plasticity and crack initiation in a single-crystal nickel-base superalloy : Modelling, evaluation and applications

   Författare :Daniel Leidermark; Kjell Simonsson; Johan Moverare; Sören Sjöström; Hannu Hänninen; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Single-crystal superalloy; Crystal plasticity; Fatigue crack initiation; Critical plane model; Theory of critical distance; Rafting; Tension compression asymmetry;

   Sammanfattning : In this dissertation the work done in the projects KME-410/502 will be presented.The overall objective in these projects is to evaluate and develop tools for designingagainst fatigue in single-crystal nickel-base superalloys in gas turbines. LÄS MER

3. 2. Computational modeling of polycrystals using gradient crystal plasticity

   Författare :Mikkel Grymer; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel algorithms; crystal plasticity; dual mixed finite element method; gradient hardening; grain modeling;

   Sammanfattning : This thesis treats the modeling of grain size dependence inmicrostructure models of metals. It is shown how gradient hardening, in a thermodynamically consistent fashion, can be included into a crystal plasticity model, which is used as the constitutive model in each grain of the polycrystal. LÄS MER

4. 3. Modelling of cyclic and viscous behaviour of materials for gas turbine applications - with a view towards fatigue life predictions

   Författare :Rebecka Brommesson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mean stress relaxation; parameter identification; Haynes 282; viscoplasticity; Ti-6242; fatigue life prediction; intergranular fracture; micromechanical model; sensitivity analysis; finite element method; Plasticity; crystal plasticity; cyclic hardening softening;

   Sammanfattning : Critical jet engine components are exposed to high temperatures. These components are also required to have low weight in order to reduce fuel consumption and allow for heavier payload, higher speed, and longer flight distance of the aircraft. LÄS MER

5. 4. Numerical Modeling of Plasticity in FCC Crystalline Materials Using Discrete Dislocation Dynamics

   Författare :Arash Hosseinzadeh Delandar; Pavel Korzhavyi; Rolf Sandström; Mikko Alava; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dislocations; crystal plasticity; discrete dislocation dynamics; Cu single crystal; high strain rate deformation; strain rate sensitivity; plastic anisotropy; slip band formation; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : Plasticity in crystalline solids is controlled by the microscopic line defects known as “dislocations”. Decisive role of dislocations in crystal plasticity in addition to fundamentals of plastic deformation are presented in the current thesis work. LÄS MER

7. 5. On computational homogenization of gradient crystal inelasticity

   Författare :Kristoffer Carlsson; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; computational homogenization; gradient theory; multiscale modeling; crystal plasticity;

   Sammanfattning : Crystal inelasticity is the main modeling technique employed to study the mechanical behavior of polycrystalline metallic materials. This class of models has the capability to represent micromechanical phenomena such as plastic slip, grain boundary interactions, and dislocation pile-up. LÄS MER