Integrated Structural Health Monitoring With Guided Waves From Piezoelectric Fibers

Active structural health monitoring of plate-like structures can be performed with ultrasonic guided waves. The activation of ultrasonic guided waves from embedded piezoelectric fibers in carbon fiber reinforced polymer (CFRP) laminated plates is investigated. Finite element analysis simulations of wave propagation from an array of embedded parallel piezoelectric fibers are presented. A quasi-isotropic CFRP having piezoelectric fibers embedded at the midplane is studied. The number and spacing of piezoelectric fibers is varied in order to activate different modes at different frequencies. The simulation results (i) characterize the displacement profile through the thickness of the CFRP plate, (ii) enable visualization of mode excitability, and (iii) demonstrate the source influence. The results indicate that the embedded fibers have a strong potential for either hot spot monitoring or distributed monitoring of large areas. However, due to the size, spacing, and activation of embedded fibers the source influence causes the mode excitability to differ from that of a conventional comb transducer.