Search for dissertations about: "surface-breaking"

Found 5 swedish dissertations containing the word surface-breaking.

  2. 1. Nonlinear Interaction Between Ultrasonic Waves and Cracks and Interfaces

    Author : Milan Poznic; Leif Kari; Bruce Drinkwater; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic waves; crack; modulation; rough interface; partially closed; surface-breaking; fluid-filled; Acoustics; Akustik;

    Abstract : The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. READ MORE

  4. 2. Modeling of Scattering by Cracks in Anisotropic Solids - Application to Ultrasonic Detection

    Author : Johan Mattsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; elastic wave; ultrasonics; crack; integral equations; transducer; anisotropy; scattering; nondestructive testing;

    Abstract : Elastodynamic wave scattering in anisotropic solids with application to ultrasonic nondestructive testing (NDT) is treated and mathematically modeled in this thesis. The scatterers are infinite strip-like cracks and the solids are homogeneous and linearly elastic with negligible damping. READ MORE

  5. 3. Analytical methods of solution to eddy current interaction problems

    Author : Lars Larsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Boundary integral equation; Scattering; T matrix; Eddy current; Nondestructive evaluation;

    Abstract : The eddy current method is used for nondestructive evaluation of conducting materials. To achieve a greater knowledge and insure safe and reliable evaluation methods, the use of mathematical models is needed. READ MORE

  6. 4. On integral equation methods of solution to eddy current interaction problems

    Author : Lars Larsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; T matrix; Boundary integral equation; Eddy current; Scattering; Nondestructive evaluation;

    Abstract : The eddy current method is used for nondestructive evaluation of conducting materials. To achieve a greater knowledge and insure safe and reliable evaluation methods, the use of mathematical models and simulations are needed. READ MORE

  7. 5. Crack growth paths in rolling contact fatigue — Numerical predictions

    Author : Mohammad Salahi Nezhad; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector crack tip displacement; Crack face friction; Crack growth direction; Crack propagation; Rolling contact fatigue;

    Abstract : Rolling contact fatigue (RCF) cracks in railway wheels and rails are costly and complex to deal with. Despite the extensive research efforts that have been put into understanding the mechanisms and developing appropriate predictive models for RCF crack growth, there are still a lot of open questions. READ MORE