Department of Mechanical Engineering 2015 Seminar Series Massimo Ruzzene, Ph.D. Professor Aerospace and Mechanical Engineering Georgia Institute of Technology Program Director Sensors, Dynamics and Control (SDC) Computational and Data-Enabled Science and Engineering (CDS&E) National Science Foundation Structural Health and Strain Monitoring Sensing Through Fourier-Based Wave Transducers Feb. 20, 2015 | 1:00 PM | DeWalt Seminar Room, 2164 Martin Hall abstract: The seminar reports on the design of a novel class of transducers for structural health monitoring and strain sensing designed using a Fourier-based approach. The design procedure formulates the problem considering an arbitrarily shaped distribution of the sensing surface. Interrogation of the sensors is based on the generation of guided and surface acoustic waves generated in the region surrounding the transducers. The representation of the distribution of the sensing material is analyzed and designed in the spatial Fourier domain, where the emission characteristics of the transducer in relation to the interrogating wave can be tailored to a specific application. For structural health monitoring, the sensing material distribution is defined to provide the transducers with frequency-dependent directional properties, which can be employed as part of an interrogation scheme based on generation and processing of guided waves in the structure. For strain sensing, one-dimensional and two-dimensional grating configurations monitor frequency shifts of radiation associated to local straining of the gratings. These frequency shifts can be related to the local strain components, so that a rosette-like configuration can be implemented. The talk illustrates the commonalities of the design procedure, which leads to novel Lamb wave and strain transducers, and suggests the potential integration of the two sensing modalities as a single device for health and usage monitoring of structural components. Massimo Ruzzene is a Professor in the Schools of Aerospace and Mechanical Engineering at Georgia Institute of Technology. He received a Ph.D in Mechanical Engineering from the Politecnico di Torino (Italy) in 1999. He is author of 2 books, 130 journal papers and about 170 conference papers. He has participated as a PI or coPI in various research projects funded by the Air Force Office of Scientific Research (AFOSR), the Army Research Office (ARO), the Office of Naval Research (ONR), NASA, the US Army, US Navy, DARPA, the National Science Foundation (NSF), as well as companies such as Boeing, Eurocopter, Raytheon, Corning and TRW. Most of his current and past research work has focused on solid mechanics, structural dynamics and wave propagation with application to structural health monitoring, metamaterials, and vibration and noise control. M. Ruzzene is a Fellow of ASME, an Associate Fellow of AIAA, and a member of AHS, and ASA. He is the program director for the Sensors, Dynamics and Control Program of CMMI at NSF. bio: www.enme.umd.edu/seminars For more information: Jin-Oh Hahn (jhahn12@umd.edu)