Multi-Gaussian Beam Effects on Transverse-to-transverse Diffuse Ultrasonic Backscatter

Speaker:
Hu, Ping; Wuhan University; China

Authors:
Hu, P.; School of Power and Mechanical Engineering, Wuhan University; China
Li, X.; School of Traffic and Transportation Engineering, Central South University; China
Li, X.; School of Power and Mechanical Engineering, Wuhan University; China
Song, Y.; School of Traffic and Transportation Engineering, Central South University; China
Turner, J.A.; University of Nebraska-Lincoln; USA

ID: ECNDT-0530-2018
Session: Microstructural Scattering - UT 2
Room: J2
Date: 2018-06-13
Time: 11:30 - 11:50

Ultrasonic scattering from interfaces within polycrystalline media contain important information that can be used to extract microstructural information by capturing the effective grain scattering. Recently, a transverse-to-transverse (T-T) model was developed for estimating the diffuse ultrasonic backscattering of the corresponding experimental pulse-echo configuration. As with previous longitudinal-to-longitudinal (L-L) and longitudinal-to-transverse (L-T) scattering models, the T-T model was used successfully to determine the material correlation length L by using the model to fit experimental results. That work shown better agreement at low frequencies suggesting insufficiencies in the theoretical model. In this presentation, the previous single-Gaussian beam (SGB) used for the T-T model is replaced with a multi-Gaussian beam (MGB). The effects of the focal length, the center frequency, and the incident angle on the Wigner transform amplitude based on the MGB are investigated in the numerical calculations. Furthermore, comparisons between SGB-TT scattering response and MGB-TT model scattering response are examined using both numerical analyses and experimental measurements. The proposed model is anticipated to extend the range of T-T ultrasonic scattering models, especially in terms of higher detection frequencies.