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Visar resultat 1 - 5 av 203 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Constitutive models based on dislocation density : formulation and implementation into finite element codes

   Författare :Konstantin Domkin; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

   Sammanfattning : Correct description of the material behaviour is an extra challenge in simulation of the materials processing and manufacturing processes such as metal forming. Material models must account for varying strain, strain rate and temperature, and changing microstructure. LÄS MER

3. 2. 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

4. 3. Calibration of constitutive models with error control

   Författare :Håkan Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In this thesis a framework for the calibration ofconstitutive models is presented. The framework involves theformulation of an optimization problem which is solved usingstrategies based on, essentially, Newton's method. LÄS MER

5. 4. Physically based constitutive models for crash of composites

   Författare :Sergio Costa; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Crushing; FEA; friction; damage mechanics; CDM; kinking;

   Sammanfattning : The transportation industry and passenger cars in particular are strong emitters of gases that contribute to the climate crisis. For this reason, the automotive industry investigates opportunities to reduce emissions, such as reducing the weight of the car. LÄS MER

7. 5. On cyclic accumulation models for degradation of railway foundations

   Författare :Hossein Tahershamsi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Natural soft clay; Global Sensitivity Analysis; Sobol method; Experimental design; Rate-dependent models; Cyclic accumulation models; Cyclic degradation; Uncertainty analysis;

   Sammanfattning : The degradation of railway foundations due to the repeated loading of traffic induces maintenance and safety obligations for the track operator. One major contributor to track degradation is the accelerated settlement rates in soft soils below the track that lead to alignment issues, especially at stiffness transitions. LÄS MER