Sökning: "dislocation density"

Visar resultat 1 - 5 av 64 avhandlingar innehållade orden dislocation density.

  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. Multiresolution Continuum Theory and Dislocation Density Based Constitutive Relations

    Författare :Hao Qin; Kenneth Runesson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Sammanfattning : In classical description, the mechanical state of a material point depends on the variables defined at this point solely. It can integrate and catch some aspects of the material’s microstructure by conventional homogenization method. LÄS MER

  4. 3. Mechanism-based flow stress model for Ti-6Al-4V : applicable for simulation of additive manufacturing and machining

    Författare :Bijish Babu; Lars-Erik Lindgren; Jean-Philippe Ponthot; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material modeling; Ti-6Al-4V; dislocation density; vacancy concentration; additive manufacturing; hot forming; heat treatment; Material Mechanics; Materialmekanik;

    Sammanfattning : Ti-6Al-4V has remarkable properties such as high specific mechanical properties (viz. stiffness, strength, toughness, fatigue resistance), corrosion resistance, biocompatibility etc. These properties make it attractive for applications in aerospace, chemical industry, energy production, surgical implants, etc. LÄS MER

  5. 4. Numerical simulation of shape rolling

    Författare :Stanislav Riljak; Stefan Jonsson; Peter Gudmundson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shape rolling; wire-rod rolling; finite-element method; generalized plane-strain; dislocation density; material model; Other materials science; Övrig teknisk materialvetenskap;

    Sammanfattning : In the first part of this thesis, the FE program MSC.Marc is applied for coupled thermomechanical simulations of wire-rod rolling. In order to predict material behaviour of an AISI 302 stainless steel at high strain rates generated during wire-rod rolling, a material model based on dislocation density is applied. LÄS MER

  7. 5. Simulation of Stainless Steel Tube Extrusion

    Författare :Sofia Hansson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Extrusion; finite element method; stainless steel; physically based material model; dislocation density; Simulering av extrusion av rostfria rör; Material Mechanics;

    Sammanfattning : The simulation of hot extrusion processes is a difficult and challenging problem in process modeling. This is due to very large deformations, high strain rates and large temperature changes during the process. LÄS MER