Damage detection on smart structures using active
thermography with optical or elastic wave excitation
Authors: G. Riegert, A. Dillenz, Th. Zweschper, G. Busse
Institute of Polymer Testing and Polymer Science (IKP), Department of
Non-Destructive Testing (ZfP), University of Stuttgart, Pfaffenwaldring 32,
D-70563 Stuttgart, Germany
Smart structures are relevant for applications in the aviation industry where they can
improve considerably stability and efficiency. The use in safety relevant areas
requires techniques of non destructive testing for condition monitoring.
Optical Lockin Thermography (OLT) provides information about thermal wave
propagation and hidden boundaries. However, if one applies Ultrasound Lockin
Thermography (ULT) the imbedded actuator itself can be used as an ultrasound
transmitter. The advantage of this method is that it responds selectively to boundary
surfaces moving with respect to each other. We show how the two techniques respond
to typical defects in laminate/actor systems.