Sökning: "large deformations"

Visar resultat 16 - 20 av 168 avhandlingar innehållade orden large deformations.

  1. 16. Fatigue crack growth experiments and analyses - from small scale to large scale yielding at constant and variable amplitude loading

    Författare :Pär Ljustell; Fred L. Nilsson; Bo Alfredsson; Gunnar Härkegård; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fracture mechanics; fatigue crack growth; finite elements analysis; small scale yielding SSY ; large scale yielding LSY ; low cycle fatigue LCF ; crack tip opening displacement CTOD ; crack closure; potential drop method; constant amplitude load; variable amplitude load; inconel 718; stainless steel 316L;

    Sammanfattning : This thesis is on fatigue crack growth experiments and assessments of fatigue crack growth rates. Both constant and variable amplitude loads in two different materials are considered; a nickel based super-alloy Inconel 718 and a stainless steel 316L. LÄS MER

  3. 17. Modeling and simulation of electro-viscoelastic polymers

    Författare :Anna Ask; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electroactive polymers; dielectric elastomer actuators; electromechanical coupling; finite elements; viscoelasticity; finite deformations;

    Sammanfattning : The electroactive polymer materials considered in this work react to electric stimuli by producing deformations. In some cases, the electrically induced deformations are moderate, while in other cases they can be very large and the specimen is stretched to more than twice its original length. LÄS MER

  4. 18. Perturbation approach to reconstructions of boundary deformations in waveguide structures

    Författare :Mariana Dalarsson; Martin Norgren; Sergei Tretyakov; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problems; waveguides; microwaves; perturbation theory; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis we develop inverse scattering algorithms towards the ultimate goal of online diagnostic methods. The aim is to detect structural changes inside power transformers and other major power grid components, like generators, shunt reactors etc. LÄS MER

  5. 19. Corotational formulation for nonlinear analysis of flexible beam structures

    Författare :Thanh Nam Le; Jean-Marc Battini; Jari Mäkinen; KTH; []
    Nyckelord :Corotational method; nonlinear dynamic analysis; beam element; large displacements; finite rotations; time stepping method; cubic interpolations;

    Sammanfattning : Flexible beam structures are popular in civil and mechanical engineering. Many of these structures undergo large displacements and finite rotations, but with small deformations. Their dynamic behaviors are usually investigated using finite beam elements. A well known method to derive such beam elements is the corotational approach. LÄS MER

  7. 20. Nonlinear dynamics of flexible structures using corotational beam elements

    Författare :Thanh-Nam Le; Jean-Marc Battini; Reijo Kouhia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; corotational method; nonlinear dynamics; large displacements; finite rotations; time stepping method; thin-walled cross-section; beam element;

    Sammanfattning : The purpose of this thesis is to develop corotational beam elements for the nonlinear dynamic analyse of flexible beam structures. Whereas corotational beam elements in statics are well documented, the derivation of a corotational dynamic formulation is still an issue. LÄS MER