Sökning: "ultrasonic waves"

Visar resultat 6 - 10 av 35 avhandlingar innehållade orden ultrasonic waves.

  1. 6. Ultrasonic NDT in Defect Detection - Mathematical modelling

    Författare :Håkan Wirdelius; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack; null field approach; transducers; optimisation; ultrasonics; elastic waves; nondestructive testing; T matrix method; inverse problem;

    Sammanfattning : This thesis is concerned with the mathematical modelling of the ultrasonic nondestructive testing situation. The first part of the thesis treats a simplified model of an ultrasonic transducer and its implementation into a T-matrix method-based solution to a crack scattering problem. LÄS MER

  3. 7. Interaction between ultrasonic waves and nonlinear cracks and interfaces

    Författare :Milan Poznic; Claudio Pecorari; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

    Sammanfattning : .... LÄS MER

  4. 8. Elastic Wave Scattering by Cracks - Interfacial Forces and High Frequency Diffraction

    Författare :Gert Persson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic testing; Wiener-Hopf calculations; Geometrical Theory of Diffraction; edge diffracted body waves; PEDGE; two-dimensional diffraction; geometrical elastodynamic waves;

    Sammanfattning : This thesis treats elastic wave scattering by cracks with interfacial forces. The results are of practical interest in ultrasonic testing and includes development of numerical methods used to predict such testing. First the canonical problem of two-dimensional (2-D) diffraction from a semi-infinite crack is solved. LÄS MER

  5. 9. Structural health monitoring of concrete structures using diffuse waves

    Författare :Patrik Fröjd; Teknisk geologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; övervakning; ultraljud; betong; diffusa vågor; oförstörande provning; structural health monitoring; ultrasound; concrete; nondestructive testing; Civil engineering; diffuse waves;

    Sammanfattning : The work presented in this thesis has aimed to investigate and implement techniques for ultrasonic measurements in structural health monitoring applications for civil structures. The focus of the work has been to make these systems practical in real applications, where the large size of the structures, and the changing environments they are exposed to, pose problems for many methods which otherwise fare well in laboratory settings. LÄS MER

  7. 10. Elastic Wave Propagation in Anisotropic Media. Application to Ultrasonic NDT

    Författare :A. Jonas Niklasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; layered media; cylinders; cracks; integral equations; scattering; nondestructive testing; elastic waves; ultrasonics; transducers; anisotropy;

    Sammanfattning : The subject of this thesis is elastic wave propagation in anisotropic materials with application to ultrasonic nondestructive testing (NDT). The first part of the thesis is concerned with modeling of ultrasonic transducers and wave propagation in anisotropic materials in general. First, a scalar 2-D case is considered. LÄS MER