Abstract
With the conspicuous advances in adhesion technologies, structural adhesion joints have been used more often replacing conventional mechanical joints such as bolted and riveted joints. Nondestructive techniques, which can detect and monitor the development of adhesive failures in-situ to evaluate the health state of adhesive joints would become increasingly important. This paper investigates the detection of the failures in the adhesive joints in a structure by applying the nonlinear piezoelectric impedance modulation method, a sensitive baseline-free structural health monitoring methodology developed by the authors. This technique evaluates failures in the structure under a pump excitation at low frequency, by measuring the current response of a piezoelectric patch on the structural surface driven by a high frequency probe voltage. Beam specimens with structural adhesive joint in healthy and debonded conditions are experimentally examined, and the resultant damage evaluation indices are investigated in terms of the probe voltage amplitudes.
