Piezoelectric Wafer Active Sensor Embedded Ultrasonics in Beams and Plates

ABSTRACT—In this paper we present the results of a sys-tematic theoretical and experimental investigation of the fun-damental aspects of using piezoelectric wafer active sensors (PWASs) to achieve embedded ultrasonics in thin-gage beam and plate structures. This investigation opens the path for sys-tematic application of PWASs for in situ health monitoring. After a comprehensive review of the literature, we present the principles of embedded PWASs and their interaction with the host structure. We give a brief review of the Lamb wave principles with emphasis on the understanding the particle motion wave speed/group velocity dispersion. Finite element modeling and experiments on thin-gage beam and plate spec-imens are presented and analyzed. The axial (S0) and flex-ural (A0) wave propagation patterns are simulated and ex-perimentally measured. The group-velocity dispersion curves are validated. The use of the pulse-echo ultrasonic technique with embedded PWASs is illustrated using both finite element simulation and experiments. The importance of using high-frequency waves optimally tuned to the sensor–structure in-teraction is demonstrated. In conclusion, we discuss the ex-tension of these results to in situ structural health monitoring using embedded ultrasonics. KEY WORDS—Piezoelectric wafers, piezoelectric sensors, active sensors, in situ diagnostics, structural health monitor-ing, piezoelectrics, ultrasonics, elastic waves, P-waves, S-waves, shear waves, axial waves, flexural waves, Rayleig

Roll Maneuver Control of UCAV Wing Using Anisotropic Piezoelectric Actuators

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76333/1/AIAA-2002-1720-656.pd