Sökning: "rate-dependent models"

Visar resultat 11 - 15 av 16 avhandlingar innehållade orden rate-dependent models.

  1. 11. Experiments and modelling of fracture initiation at impact

    Författare :Ola Wall; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Viscoplasticity; Mechanical engineering; Ductile; Brittle; Dynamic; Fracture; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Material technology; Materiallära; materialteknik;

    Sammanfattning : The thesis addresses different questions, each necessary in the understanding of dynamic fracture initiation and crack propagation in steel. Emphasis lays on dynamic crack propagation experiments performed in the ductile to brittle transition region and possible conclusions, that can be drawn from them. LÄS MER

  3. 12. Towards energy-based fracture modelling for crashworthiness applications

    Författare :Simon Jonsson; Jörgen Kajberg; Stefan Golling; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : The automotive industry is currently adapting to progessively more stringent emission and safety regulations imposed by governmental agencies. This introduces significant design difficulties due to the conflicting nature of passenger safety in automotive manufacturing, namely that increased crashworthiness generally leads to heavier vehicles, which in turn leads to more severe crashes. LÄS MER

  4. 13. Modeling of Inelastic Response of Metals with Emphasis on Cyclic Viscoplasticity

    Författare :Magnus Ekh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large strains; integration; anisotropy; plasticity; creep; viscoplasticity; kinematic hardening; metals; damage; calibration;

    Sammanfattning : This thesis is concerned with the continuum modeling of the macroscopic behavior of engineering metals, in particular as part of life prediction strategies. Focus is primarily placed on the formulation and numerics of models for cyclic rate-dependent response. LÄS MER

  5. 14. Concrete Structures Subjected to Fragment Impacts

    Författare :Joosef Leppänen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perforation; penetration; strain rate; scabbing; dynamic loading; fragment and projectile impacts; numerical simulations; spalling; concrete; blast wave;

    Sammanfattning : As concrete is commonly used for protective structures, how a blast wave and fragment impacts from an explosion affect the concrete is an important issue. Concrete subjected to explosive loading responds very differently from statically loaded structures. LÄS MER

  7. 15. Brain injury biomechanics in closed-head impact : studies on injury epidemiology, tolerance criteria, biomechanics and traffic injury prevention

    Författare :David Viano; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Closed-head impact; brain injury; biomechanics; injury mechanisms; tolerance criteria; epidemiology; and primary prevention.;

    Sammanfattning : Permanent disability from traumatic brain injury is a devastating consequence of traffic crashes. Injury prevention is a fruitful approach to reduce the incidence and severity of disabling brain injury. LÄS MER