Sökning: "elastic wave"

Visar resultat 1 - 5 av 92 avhandlingar innehållade orden elastic wave.

  1. 1. Transmission of waves through elastic and viscoelastic junctions

    Författare :Tomas Nygren; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Wave; elastic; viscoelastic; extensional; characteristic impedance; junction; transmission; reflection; dissipation; optimisation; Materialvetenskap; Materials science; Teknisk materialvetenskap; Solid Mechanics; hållfasthetslära;

    Sammanfattning : Transmission of extensional waves through elastic and viscoelastic junctions between elastic and collinear bars have been studied theoretically and experimentally. The models used can be interpreted also for other types of waves (e.g. dilatational waves, shear waves, electromagnetic waves) and systems. LÄS MER

  3. 2. Numerics of Elastic and Acoustic Wave Motion

    Författare :Kristoffer Virta; Gunilla Kreiss; Anders Petersson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite differences; stability; high order accuracy; elastic wave equation; acoustic wave equation; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The elastic wave equation describes the propagation of elastic disturbances produced by seismic events in the Earth or vibrations in plates and beams. The acoustic wave equation governs the propagation of sound. LÄS MER

  4. 3. Estimation of state and identification of complex modulus based on measurements om a bar traversed by waves

    Författare :Lars Hillström; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Wave; extensional; flexural; bar; rod; beam; elastic; viscoelastic; complex modulus; non-parametric; parametric; standard deviation; Materialvetenskap; Materials science; Teknisk materialvetenskap; Solid Mechanics; hållfasthetslära;

    Sammanfattning : Estimation of state and identification of complex modulus based on measurements on non-uniform rods and beams have been studied theoretically and experimentally. Two principal cases were studied. In the first case, the material properties are fully known and the state at a section is to be estimated. LÄS MER

  5. 4. Thin Layers in Elastic Wave Propagation -Effective Modelling and Diffraction

    Författare :Peter Bövik; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Geometrical Theory of Diffraction; elastic wave scattering; shear waves; Wienr-Hopf method; L-TV waves; applications;

    Sammanfattning : In the present thesis, the interest is focussed on the problem of effective modelling of thin interface layers for applications in elastic wave scattering. The layers are considered to be thin compared with wavelengths involved and it is shown that when all effects to lowest order in the layer thickness are included, we get boundary conditions (BCs) which have a number of nice features, including the one of implying that no scattering occurs when the layer has material parameters identical to the ones in the matrix medium. LÄS MER

  7. 5. Wave-actuated Preform Infiltration Routines in MMC Production

    Författare :Lars-Olov Pennander; Industriell Produktion; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material technology; Magnetostrictive; Vibration; Actuation; Wave; Infiltration; Preform; Metal; Composites; MMC; Materiallära; materialteknik;

    Sammanfattning : The implementation of highly magnetostrictive wave-actuator techniques in preform infiltration processes for metal-matrix composite production is described. Metal matrix materials require additional methods to handle the content, shape and position of the ceramic reinforcements, which are not required for metal alloy casting. LÄS MER