Papers by Keyword: Multi Gaussian Beam

Abstract: The objective of this paper is to predict the flaw response in an inhomogeneous solid medium. Multi-Gaussian Beam (MGB) model is used to represent the incident ultrasonic beam. The effect of ultrasonic attenuation and phase velocity dispersion due to grain scattering is included in the predictions. The effect of variation of mean diameter of the grains on the received voltage for different domain of interest is studied through the experimental results.

Abstract: Ultrasonic methods are used in a wide variety of applications including medical studies, geological mapping, and nondestructive evaluation (NDE) tests. In the field of ultrasonic NDE, it is necessary to treat inverse problems of various types. The objective of this paper is to predict the flaw response in an inhomogeneous solid medium. A mathematical modelling of the testing situation is very valuable for a number of reasons. The modelling helps in developing physical intuition and in the interpretation of tests. Multi-Gaussian Beam (MGB) model is used to represent the incident ultrasonic beam. The effect of ultrasonic attenuation and phase velocity dispersion due to grain scattering is included in the predictions. The variation of received voltage is analyzed against the distance of the flaw from the transducer for different dimensions of a square cylinder void. The effect of variation of mean diameter of the grains on the received voltage for different domain of interest is also studied.

Abstract: For the reliable application of ultrasonic phased array technique, it is necessary to understand the characteristics of the radiation beam field from the array transducers quantitatively. Very recently, it has been developed the expanded multi-Gaussian beam model that can calculate the radiation beam field from a single, rectangular transducer with great computational efficiency. In this paper, this model is adopted to calculate the radiation beam field from array transducers with various time delays to achieve steering and/or focusing. The calculation results are compared to those obtained by well known Rayleigh-Sommerfeld integral that provides the exact solution in order to explore the validity of the expanded multi-Gaussian beam model in this task.