Multi-mode Damage Detection Methods with Piezoelectric Wafer Active Sensors

ABSTRACT: PWAS are small and non-invasive transducers that can be easily affixed to a structure to interrogate it at will. Their wideband non-resonant properties make them advantageous candidates for multiple modes structural health monitoring (SHM) and non-destructive evaluation (NDE) simply by changing the driving frequencies. This paper presents research results obtained by using PWAS transducer for SHM/NDE. The results are given in the following directions: (1) PWAS operation principles; (2) PWAS electromechanical impedance measurements; (3) PWAS ultrasonic SHM/NDE; and (4) PWAS multi-mode corrosion detection. The analytical methods and experimental results can be successfully used in the design of active SHM systems to be embedded on operational structures, such as aircraft panels