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This paper starts a review of the state of the art in structural health monitoring with piezoelectric wafer active sensors and follows with highlighting the limitations of the current approaches which are predominantly experimental. Subsequently, the paper examines the needs for developing a predictive modeling methodology that would allow to perform(More)
The use of piezoelectric wafer active sensors (PWAS) phased arrays for Lamb wave damage detection in thin-wall structures is presented. The PWAS capability to tune into specific Lamb-wave modes (which is an enabling factor for our approach) is first reviewed. Then, a generic beamforming formulation that does not require the conventional parallel-ray(More)
A Vibration Management Enhancement Program (VMEP) effort is currently under way at the South Carolina Army National Guard, Army Aviation Support Facility (SCARNG-AASF) in cooperation with the University of South Carolina (USC). The purpose of the program is to minimize aircraft operation cost, reduce maintenance flights, augment aircraft availability, and(More)
Health monitoring methods using active sensors (e.g. piezoelectric transducers) and wavelet transforms are being developed in the Department of Mechanical Engineering at the University of South Carolina. In these methods, wave propagation signals are collected using arrays of piezoelectric transducers placed on or embedded in a structure. The collected(More)
The emerging electro-mechanical impedance technology has high potential for in-situ health monitoring and NDE of structural systems and complex machinery. At first, the fundamental principles of the electro-mechanical impedance method are briefly reviewed and ways for practical implementation are highlighted. The equations of piezo-electric material(More)
This paper presented development work of an in situ method for damage detection in thin-wall structures using embedded two-dimensional ultrasonic phased arrays. Piezoelectric wafer active sensors were used to generate and receive guided Lamb waves propagating in the plate-like structure. The development of a generic beamforming algorithm that does not(More)
A project to develop non-intrusive active sensors that can be applied on existing aging aerospace structures for monitoring the onset and progress of structural damage (fatigue cracks and corrosion) is presented. The state of the art in active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave(More)
A study of published literature and information from piezoelectric, electrostrictive, and magnetostrictive actuator vendors has been undertaken to establish the mechanical and electrical operating characteristics of the actuators under quasi-static conditions, and to compare them using output energy density criteria. Output energy values of up to 0.720 J(More)
Piezoelectric Q2 wafer active sensors are lightweight and inexpensive enablers for a large class of structural health monitoring applications such as 1) embedded guided-wave ultrasonics, i.e., pitch–catch, pulse–echo, and phased arrays; 2) high-frequency modal sensing, i.e., the electromechanical impedance method; and 3) passive detection (acoustic emission(More)