Piezoelectric Rosettes for Acoustic Source Location in Composite Structures: Results from “Blunt†Impact Tests

Abstract

Over the past few years, the authors have investigated the technique of Piezoelectric Rosettes for localization of AE sources. The rosettes use the directivity behavior of rectangular piezo-composite patches to yield the principal strain angle of the incoming AE wave without the need for wave velocity information. The use of at least two rosettes allows one to pinpoint the AE source location. Because the rosette-based AE source location algorithm is not dependent on the wave velocity, the method lends itself to monitoring complex composite structures where the velocity can change with wave propagation direction (anisotropy) or along the wave propagation path (tapered and multilayered geometries). This paper presents the AE source location results from “blunt†impact tests conducted on two large curved CFRP composite panels with co-cured stiffeners and bolted shear ties of overall dimensions of 1 m × 1 m and 1.93 m × 1.42 m, respectively. The results of these tests are of interest to follow the evolution of damage during the impact events.