Search for dissertations about: "dislocation density"

Showing result 1 - 5 of 49 swedish dissertations containing the words dislocation density.

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

    University dissertation from Luleå : Luleå tekniska universitet

    Author : Konstantin Domkin; [2005]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computer Aided Design; Datorstödd maskinkonstruktion;

    Abstract : 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. READ MORE

  2. 2. Multiresolution Continuum Theory and Dislocation Density Based Constitutive Relations

    University dissertation from Luleå tekniska universitet

    Author : Hao Qin; Luleå tekniska universitet.; [2016]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

    Abstract : 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. READ MORE

  3. 3. Numerical simulation of shape rolling

    University dissertation from Stockholm : KTH

    Author : Stanislav Riljak; KTH.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shape rolling; wire-rod rolling; finite-element method; generalized plane-strain; dislocation density; material model; TECHNOLOGY Materials science Other materials science; TEKNIKVETENSKAP Teknisk materialvetenskap Övrig teknisk materialvetenskap;

    Abstract : 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. READ MORE

  4. 4. Simulation of stainless steel tube extrusion

    University dissertation from Luleå : Luleå tekniska universitet

    Author : Hansson Sofia; Sofia Hansson; Luleå tekniska universitet.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Simulering av extrusion av rostfria rör; Extrusion; finite element method; stainless steel; physically based material model; dislocation density; Material Mechanics; Materialmekanik;

    Abstract : 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. READ MORE

  5. 5. Toward first-principles understanding of carbonitride precipitation in steels

    University dissertation from Chalmers University of Technology

    Author : Dan Fors; Chalmers tekniska högskola.; Chalmers University of Technology.; [2008]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Defekter och diffusion; Defects and diffusion; Ytor och mellanytor; Surfaces and interfaces; Steels; Coarsening; Precipitates; Electronic structure; Interfaces; Density functional theory; Diffusion; Dislocation network; Peierls-Nabarro model; Misfit;

    Abstract : The most important and widely used group of metallic alloys is steels, which are alloys of the element iron together with carbon and usually other elements such as B, N, V, Nb and Cr. The strength in these alloys is closely connected to the distribution of point defects, precipitates and grain boundaries which effectively act as obstacles for dislocation migration. READ MORE