Damage detection potential of a triangular piezoelectric configuration

In this work a problem of damage detection and localization was investigated. A new configuration of piezoelectric transducers was proposed. It consists of twelve transducers. It is in a form of an equilateral triangle that has a 2 x 2 transducer array in each vertex. Transducers of this configuration were used to excite and register guided waves in an aluminum alloy specimen. Due to known sensitivity of these waves to structural defects it was assumed that registered waves, in the form of voltage signals, carry information about the structure condition. A special algorithm was implemented to process these signals and extract features related to damage. This algorithm transfers information from the time domain to the spatial domain. Results are mapped into coordinate system assigned to monitored structure. In this way in the case of damage present outside or inside the configuration its coordinates are highlighted. In order to detect damage on the direct path between triangle vertices a damage index is defined that indicates whether there is damage present or not. Experimental investigation included three scenarios, one for outside and one for inside localization and one for direct path detection. Results showed that this method has a potential for Structural Health Monitoring of a structure made of an isotropic material. (C) 2011 Elsevier Ltd. All rights reserved.