Damage Detection in Concrete Using Diffuse Ultrasound Measurements and an Effective Medium Theory for Wave Propagation in Multi-phase Materials

ACKNOWLEDGEMENTS Without the help and support from a large number of people, this work would not have been possible. First of all, I would like to thank Prof. Laurence Jacobs for making this exchange possible and for being a great advisor, supporter, teacher and friend. He opened a new door to ultrasonic wave propagation I might not have entered without him. A huge 'Thank You' goes to Dr. Jin-Yeon Kim for his advice on experimental procedures and the sharing of his knowledge, but just as important for his moral support when times were not so bright. for organizing the exchange and his help to get through the necessary formalities to go to school on a different continent. The support of Jan Herrmann (also at the IAM) in the preparation of my stay here is also appreciated. My studies would not have been possible without the very generous financial support by the DAAD (German Academic Exchange Service). deserve my gratefulness for helpful advice and support with experiments. I would also like to thank Robert Moser for supplying the samples employed in this research. Also, the people in the CEE and ME machine shop who manufactured the cones and the fixture have to be mentioned and their help is greatly appreaciated. I would like to express my gratitude to my labmates Martin Mueller, Alexander iii Pertsch, Natalie Darraugh and Minghe Liu for the nice working environment and the fun we had together. Also I want to thank my friends and roommates who cheered me up when necessary and who will be missed when I leave Georgia Tech. Last but not least, I want to express my loving gratitude to my family who always stood behind me and supported me. Their belief in me literally took me to new worlds. 7.2 Simulation of the energy density evolution with the infinite plate solution 51 7.3 Simulation of the energy density evolution with the finite cuboid solution 52