A feasibility study of PVDF piezoelectric sensors to detect damage in adhesive joints

Poly(vinylidene fluoride) (PVDF) films can be easily etched into sensor devices. Since these sensors are relatively inexpensive, thin and light-weight, they can be attached to adhesively bonded joints permanently to measure bond integrity. The present study shows the different steps to design such sensors and proper techniques to attach them near the adhesive bondline. PVDF sensors have been successfully used as NDT transducers in pulse-echo, through-transmission, and acousto-ultrasonic techniques to monitor curing, to detect porosity and crack propagation in different model joint geometries. The potential of using these techniques for practical bonded structures has then been evaluated.