Frequency Steerable Acoustic Transducers for Structural Health Monitoring
Smart Materials and Systems Seminar Series
Dr. Massimo Ruzzene
D. Guggenheim School of Aerospace Engineering, G.W. Woodruff School of Mechanical Engineering
Georgia Institute of Technology
Frequency Steerable Acoustic Transducers (FSATs) are novel sensors and actuators for wave-based nondestructive evaluation (NDE) and structural health monitoring (SHM). FSATs are capable of focusing and steering ultrasound with a simple frequency sweep, rather than phasing arrays of tens to hundreds of actuators and sensors. This results in great reductions in power, data handling and transmission, wiring, electronics, cost, size, and weight. Thus, FSATs can offer a cost effective means for permanently mounted, remote or embedded, wireless NDE and SHM.
The considered FSAT design is characterized by a spiral configuration in wavenumber domain, which leads to a spatial arrangement of the sensing material producing output signals whose dominant frequency component is uniquely associated with the direction of incoming waves. Analytical expression of the shape of the spiral FSAT is developed and subsequently tested by forming a discrete array through the points of the measurement grid of a Scanning Laser Doppler Vibrometer. The experimental results demonstrate the strong frequency dependent directionality of the spiral FSAT and suggest its application for frequency selective acoustic sensors, to be employed for the localization of broadband acoustic events, or for the directional generation of Lamb waves for active interrogation of structural health.
About the Speaker
Massimo Ruzzene is an Associate Professor in the Schools of Aerospace and Mechanical Engineering at Georgia Institute of Technology. He received a PhD in Mechanical Engineering from the Politecnico di Torino (Italy) in 1999. He is author of approximately 90 journal papers and more than 120 conference paper. He has participated as a PI or co-PI 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, TRW Corporation and the National Science Foundation (NSF). Most of his current and past research work has dealt with structural health monitoring, wave propagation analysis, high frequency vibration modeling, and vibration and noise control techniques.