Evaluation of PTCa/PEKK composites for acoustic emission detection

The electromechanical properties of calcium modified lead titanate/poly(ether ke-tone ketone) (PTCa/PEKK) composites and their ability after poling to detect acoustic emission (AE) when mounted on carbon fiber reinforced composite (CFRC) panels is reported. They have been characterized by measurements of conductance, G, permittivity, /spl epsi/, pyroelectric, p, and piezoelectric, d/sub 33/, coefficients for different ceramic volume fractions. In addition, the electromechanical coupling coefficient, k/sub t/, the elastic compliance coefficient, s/sub 33/, the acoustic impedance, Z/sub a/, and the quality factor coefficient, Q/sub m/ have been calculated from the measurement of the complex impedance (Z) of the composite samples acting as free resonating transducers. It is demonstrated that in a square array they can be used to locate AE sources with good accuracy and that they will also detect AE caused by the delamination of a CFRC beam.