The PI is particularly interested in the development of practical diagnostic techniques for structures because this work draws upon her expertise in nondestructive testing, stress wave propagation, fracture mechanics, dynamic finite element analysis and structural engineering. To date, the impact-echo method to locate flaws in platelike, reinforced concrete structures, such as pavements, walls, and slabs, have been used. The PI will determine the feasibility of using the impact-echo idea for evaluating the quality of and detecting cracking in reinforced concrete structures, such as locks and dams, large foundations and bridge piers, and offshore structures. Initial research will involve using an existing three-dimensional, transient finite element code to develop an understanding of how stress waves propagate in these types of structures and how the response of the structures changes when defects are present. Currently, no solutions exist for any of these problems. Once this under- standing has been developed, experimental studies of small models of larger structures with and without flaws will be carried out. Finally, the results of the field studies will be checked by coring or other techniques to verify the results.
