Sökning: "nonlocal response"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden nonlocal response.

  1. 1. Graphene plasmons in nanostructured environments

    Författare :Tobias Wenger; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlocal response; Graphene plasmons; subwavelength electromagnetic scattering; linear response Green s functions;

    Sammanfattning : This thesis explores the combination of electromagnetism with electrons in graphene. Graphene is a one atom thick layer of carbon atoms which contains electrons that exhibit rather special properties in terms of their conduction abilities. LÄS MER

  3. 2. Plasticity and Damage Mechanics for Modeling Concrete Failure

    Författare :Peter Grassl; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlocal; concrete; localization; plasticity; damage;

    Sammanfattning : Concrete structures exhibit strongly non-linear and complex mechanical behavior. Hence, they are nowadays often analyzed by means of the finite element method, whereby a realistic description of the material behavior is decisive for the validity of the results. LÄS MER

  4. 3. Modelling of fracture toughness using peridynamics : A Study of J-integral, essential work and homogenisation

    Författare :Christer Stenström; Pär Jonsén; Kjell Eriksson; Ugo Galvanetto; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Peridynamics; J-integral; Essential work of fracture; Nonlocal methods; Meshless; Meshfree; Fracture; Crack tip; Exact analytical; Center cracked tension; Double edge notched tensile; fracture toughness; Peridynamik; Brottmekanik; Sprickspets; Brottseghet; Spänningsintensitet; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Fracture toughness is one of the most important properties of a material. Being able toaccurately estimate the energy that goes into forming new crack surfaces is essential for the development of new materials, quality assurance, structural monitoring and failure analysis. LÄS MER

  5. 4. First-principles calculations of polymer interactions

    Författare :Jesper Kleis; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; polymer structure; polyvinylchloride.; polypropylene; polyethylene; sparse material systems; Density functional theory; polymer interactions; van der Waals interaction; polymer crystal; soft matter; DFT;

    Sammanfattning : This thesis reports on studies of interactions in sparse matter by first-principles calculations, in particular polymeric systems. The focus is on the three unbranched simple polymers: polyethylene (PE), isotactic polypropylene (PP) and isotactic polyvinylchloride (PVC), which together represent an important class of materials that form complexes stabilized by weak but long-range dispersive interactions. LÄS MER

  7. 5. Numerical modeling of auroral processes

    Författare :Jörgen Vedin; Kjell Rönnmark; Robert Lysak; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; space plasma physics; auroral acceleration region; auroral current circuit; Alfvén waves; parallel electric fields; equation of state; fluid simulation; PIC simulation; Space physics; Rymdfysik;

    Sammanfattning : One of the most conspicuous problems in space physics for the last decades has been to theoretically describe how the large parallel electric fields on auroral field lines can be generated. There is strong observational evidence of such electric fields, and stationary theory supports the need for electric fields accelerating electrons to the ionosphere where they generate auroras. LÄS MER