|SUBJECT:||M.S. Thesis Presentation|
|TIME:||Tuesday, March 25, 2014, 4:00 p.m.|
|PLACE:||Georgia Tech Lorraine, France, Pink|
|TITLE:||Ice thickness estimation using low frequencies, and an investigation of diffraction of sound in samples with micro structures using ultrasound|
|COMMITTEE:||Dr. Nico F. Declercq, Chair (ME)
Dr. Massimo Ruzzene (AE/ME)
Dr. Badreddine Assouar (Université de Lorraine)
In the first section, the thickness of ice on the lakes and canals is estimated by analyzing the sound spectrum generated by dispersion of Lamb type waves propagating in ice. In winters when the lakes and canals freeze, it is important to know the thickness of the ice layer before setting foot on it. When a stone is thrown on the ice layer, a fluting sound can be heard. This is recorded for different thicknesses of ice, and the sound spectrum is compared with the results simulated using a parameterized model. This model is created using a combination of plane waves for different incident angles and frequencies to generate dispersion curves for different thicknesses of ice. The frequencies of the reflected sound are then compared with the frequencies of musical instruments in order to assign different musical notes to different thicknesses of ice. The technique enables thickness estimation without the use of specialized equipment or time consuming drilling and may therefore be of practical value in the preservation of the lives of ice skaters and playing children. In the second half of the study, high frequencies (400 MHz and 1 GHz) are used to investigate samples with micro structures.