Temperature dependency of impedance-based nondestructive testing

Through a series of experiments presented in this paper, the impedance-based non-destructive testing technique can be used to identify damage in laminated composites at low temperature. However, regular piezoceramic patches have been found to be unsuitable for damage detection at cryogenic temperatures. For impedance-based nondestructive testing on composite laminates at true cryogenic environments, the results presented in this paper suggest that an alternative type of actuator based on smart materials should be sought. The piezoceramic transducer for cryogenic environments should be able to produce good impedance measurements at cryogenic temperatures without much noise. The authors are conducting an on-going research program to identify such a material.