Search for dissertations about: "ultrasonic nondestructive testing"

Showing result 1 - 5 of 13 swedish dissertations containing the words ultrasonic nondestructive testing.

  1. 1. Maximum a posteriori deconvulution of ultrasonic data with applications in nondestructive testing : Multiple transducer and robustness is

    Author : Tomas Olofsson; Uppsala universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Materials science; Ultrasonic pulse-echo testing; nondestructive testing; maximum a posteriori estimation; linear minimum mean squared error estimation; robust filtering; multivariable filtering; sparse deconvolution; Materialvetenskap; Materials science; Teknisk materialvetenskap; Signal Processing; signalbehandling;

    Abstract : In the thesis, various aspects of deconvolution of ultrasonic pulse-echo signals in nondestructive testing are treated. The deconvolution problem is formulated as estimation of a reflection sequence which is the impulse characteristic of the inspected object and the estimation is performed using either maximum a posteriori (MAP) or linear minimum mean square error (MMSE) estimators. READ MORE

  2. 2. Modelling of ultrasonic testing for cracks near a non-planar surface

    Author : Jonathan Westlund; Chalmers University of Technology; []
    Keywords : Ultrasonics; BIEM; Elastic waves; Nondestructive testing; Crack; BEM.;

    Abstract : Nondestructive testing using ultrasound has important applications in e.g. the nuclear power and aerospace industries, where it is used to inspect safety-critical parts for flaws. READ MORE

  3. 3. On the modelling of ultrasonic testing using boundary integral equation methods

    Author : Jonathan Westlund; Chalmers University of Technology; []
    Keywords : Boundary element method; Regularization; Ultrasonics; Boundary integral equation method; T matrix.; Elastic waves; Nondestructive testing; Scattering;

    Abstract : Ultrasonic nondestructive testing has important applications in, for example, the nuclearpower and aerospace industries, where it is used to inspect safety-critical parts for flaws.For safe and reliable testing, mathematical models of the ultrasonic measurement systemsare invaluable tools. READ MORE

  4. 4. Ultrasonic NDT in Defect Detection - Mathematical modelling

    Author : Håkan Wirdelius; Chalmers University of Technology; []
    Keywords : crack; null field approach; transducers; optimisation; ultrasonics; elastic waves; nondestructive testing; T matrix method; inverse problem;

    Abstract : 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. READ MORE

  5. 5. Elastic Wave Propagation in Anisotropic Media. Application to Ultrasonic NDT

    Author : A. Jonas Niklasson; Chalmers University of Technology; []
    Keywords : layered media; cylinders; cracks; integral equations; scattering; nondestructive testing; elastic waves; ultrasonics; transducers; anisotropy;

    Abstract : 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. READ MORE