Sökning: "background inertia"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden background inertia.

  1. 1. Dynamic neck formation in elastic-plastic tensile bars

    Författare :Kristina Nilsson; Mekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic loading; necking; inertia; localization zones; numerical simulation; finite elements; non-linear;

    Sammanfattning : The time development of neck formation in ductile elastic-plastic bars is analyzed numerically in order to obtain a qualitative description of the features of dynamic neck localization under impact conditions. The full time history is visualized using contour plots of the time development of a strain rate parameter. LÄS MER

  3. 2. Simulation of dynamic instabilities during high rate deformation of ductile bars and plates

    Författare :Kristina Nilsson; Mekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical simulation; non-linear; wave propagation; multiple necking; necking; buckling; fracture; Mechanical engineering; Maskinteknik; finite elements; cohesive elements; dynamic; J2-flow theory; J2-deformation theory; viscoplastic; background inertia;

    Sammanfattning : In this thesis, some of the phenomena occurring in plates and cylindrical bars subjected to dynamic loading are investigated. Numerical simulations using a dynamic finite element code are performed for a number of different sized specimens with various initial surface imperfections. Typically imposed loading velocities are in the range 10m/s.. LÄS MER

  4. 3. Change and inertia in the development of Swedish engineering education : The industrial stakeholder perspective

    Författare :Per Fagrell; Lars Geschwind; Anders Broström; Jennifer Case; KTH; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Teknikvetenskapens lärande och kommunikation; Education and Communication in the Technological Sciences;

    Sammanfattning : This thesis investigates higher education development in Sweden from an external stakeholder perspective, with a particular focus on engineering education. Industry has long been a major external stakeholder in the development of profession-oriented higher education, not least in the context of engineering education. LÄS MER

  5. 4. Superfluidity and Supersolidity in Ultracold Atomic Gases Beyond Mean Field

    Författare :Mikael Nilsson Tengstrand; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bose-Einstein condensation; superfluidity; supersolidity; ultracold atomic gases; dipolar gases; binary Bose mixtures; quantum droplets; beyond mean field; quantum fluctuations; Fysicumarkivet A:2022:Nilsson;

    Sammanfattning : This thesis investigates ultracold bosonic systems using an extended mean-field formalism with a focus on their superfluid and supersolid properties. The dissertation comprises five chapters and four articles, where the chapters provide some background to the research put forward in articles. LÄS MER

  7. 5. Nitrogen land-sea fluxes in the Baltic Sea catchment : Empirical relationships and budgets

    Författare :Hanna Eriksson Hägg; Christoph Humborg; Carl-Magnus Mörth; Hans Borg; Sybil Seitzinger; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen fluxes; Baltic Sea; primary emissions; riverine export; Scenario analysis; climate change; animal protein consumption; fertilizer use; Environmental chemistry; Miljökemi; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : In this thesis empirical relationships and modeling tools are used to describe the relationship between human activities and meso- and large scale riverine N fluxes from land to sea. On a large scale Paper I showed that by only having knowledge about human population size and runoff one can estimate the riverine export of DIN (r2= 0.76). LÄS MER