Search for dissertations about: "elastic wave scattering"

Showing result 6 - 10 of 27 swedish dissertations containing the words elastic wave scattering.

  2. 6. Scattering of elastic waves by an anisotropic sphere with application to polycrystalline materials

    Author : Ata Jafarzadeh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spherical obstacle; Anisotropy; Attenuation; Polycrystalline materials; Effective wave number; T matrix; Phase velocity; Scattering;

    Abstract : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in various branches of physics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complex structures like particulate composites or grainy materials, which may have applications in non-destructive testing, material characterization, medical ultrasound, etc. READ MORE

  4. 7. Elastic Wave Scattering by Closed Cracks and Thin Flaws - Multiple Scattering and Resonances

    Author : Arne S. Eriksson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SH-wave; evaluation of materials; direct integral equation; singularity expansion; ultrasonic testing;

    Abstract : In this thesis we study elastic wave scattering by thin flaws and closed cracks, which finds applications in ultrasonic testing and evaluation of materials. First we consider the scattering of an SH-wave by a thin finite elastic layer between two elastic half-spaces. READ MORE

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

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

    Abstract : 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. READ MORE

  6. 9. New Methods for Reducing Ground-Borne Noise in Buildings above Railway Tunnels

    Author : Osama A. B. Hassan; KTH; []
    Keywords : Ground-borne noise; railway noise; in-plane waves; wave-guides; scattering; propagation constant; input mobility; elastic stratum; dual integral equations;

    Abstract : The rapid expansion of major cities in the west Europeancountries has accentuated the need to exploit every potentialsite for new establishments, e.g. areas over train tunnels andnear railway tracks in general. READ MORE

  7. 10. High-sensitivity Radioactive Xenon Monitoring and High-accuracy Neutron-proton Scattering Measurements

    Author : Cecilia Johansson; Jan Blomgren; Nils Olsson; Allena Opper; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; Monte Carlo simulations; MCNP; xenon detection; detector response; neutron detection; elastic scattering; differential cross section; Kärnfysik; Nuclear physics; Kärnfysik;

    Abstract : Two aspects of applied nuclear physics have been studied in this thesis; Monte Carlo simulations for high-sensitivity monitoring of radioactive xenon and high-accuracy neutron-proton scattering measurements for neutron physics applications and fundamental physics. The Monte Carlo simulations have been performed for two systems for detection of radioactive xenon, using the MCNP code. READ MORE