Identification of delamination in a composite beam using integrated piezoelectric sensor/actuator layer

This paper describes the use of an integrated piezoelectric sensor/actuator (IPSA) layer to detect a delamination in a laminated composite beam by monitoring the sensor charge output (SCO) distributions along the beam of the first three order frequencies. For the sake of predicting the first three order frequencies and SCO distributions using the IPSA layer, a model-based delamination detection approach is presented. The corresponding dynamic analytical model that includes parameters characterizing delamination is developed using the classical beam theory and the assumption of constant peel and shear strains through the bond line thickness in bonded joint. Using the present analytical model, the effects of delamination length ld, delamination gap tg, actuator segment length la, actuator segment location Xa and electric field E on the SCO values are discussed. Finally, a comparison of the first three order frequencies between the present analytical and finite element analysis (FEA) models reveals that there is good agreement between these two models.