Application of NDE techniques to assess the environmental durability of structural adhesive joints

摘要

Metal to metal and composite adhesive joints representing numerous types of adhesives and surface pre-treatments were exposed to harsh environmental conditions, and several non-destructive techniques were applied to follow their degradation and assess their condition. The experimental results and some of the consequent analyses are described, and an emphasis is given to our approach of deciphering useful information about the joints through the entropy of their corresponding ultrasonic signals, calculated by means derived from the zero-crossing method for signal analysis.