Sökning: "Vetenskaplig. Teknisk"

Visar resultat 21 - 25 av 4059 avhandlingar innehållade orden Vetenskaplig. Teknisk.

  1. 21. Importance of the particle shape on mechanical properties of soil materials

    Författare :Juan Rodriguez; Sven Wallman; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soil Mechanics; Geoteknik;

    Sammanfattning : Particle shape of soil aggregates is known to influence several engineering properties; such as the internal friction angle, the permeability, etc. Even if this is known, there has been only minor progress in explaining the processes behind its performance and has only partly implemented in practical geotechnical analysis. LÄS MER

  3. 22. Heritagisation of built environments : a study of the urban transformation in Kiruna, Sweden

    Författare :Jennie Sjöholm; Krister Olsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Architecture; Arkitektur;

    Sammanfattning : This licentiate thesis is part of a larger case study that examines the built cultural heritage in Kiruna’s urban transformation. The research study presupposes it is necessary to address cultural significance of the built environment in urban planning practice. LÄS MER

  4. 23. Transients in high head Francis turbines

    Författare :Chiragkumar Trivedi; Fredrik Engström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : On demand energy market and favourable government policies to encourage the usage of renewable energy have led to a dramatic increase of grid connected wind, solar, and other power in recent years. Penetration of the power above manageable limit, produced using intermittent energy sources, to meet the demand has induced instable grid operations. LÄS MER

  5. 24. On efficient and adaptive modelling of friction damping in bladed disks

    Författare :Mohammad Afzal; Leif Kari; Ines Lopez Arteaga; Muzio M Gola; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High cycle fatigue; Friction contact; Jacobian matrix; Shroud contact; Strip damper; Multiharmonic balance method; Contact stiffness; Cyclic symmetry; Nodal diameter; Magnetostrictive actuator; Magnetic field; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : This work focuses on efficient modelling and adaptive control of friction damping in bladed disks. To efficiently simulate the friction contact, a full-3D time-discrete contact model is reformulated and an analytical expression for the Jacobian matrix is derived that reduces the computation time drastically with respect to the classical finite difference method. LÄS MER

  7. 25. Mechanical Behaviour of Adhesive Layers : Methods to Extract Peel and Mixed Mode Properties

    Författare :Tobias Andersson; Högskolan i Skövde; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering mechanics; Teknisk mekanik; Teknik; Technology;

    Sammanfattning : Mechanical Behaviour of Adhesive Layers Methods to Extract Peel and Mixed Mode Properties TOBIAS ANDERSSON Department of Applied Mechanics Chalmers University of Technology ABSTRACT This thesis is concerned with methods to extract material properties of thin adhesive layers loaded in peel and in mixed mode. The first part of the thesis is devoted to an experimental method to determine the complete stress-elongation relation (or cohesive law) for an adhesive layer loaded in peel using the DCB-specimen. LÄS MER