Vibro-Acoustic Modulation NDE Technique. Part 1: Theoretical Study

Vibro‐modulation involves monitoring the amplitude modulation of an ultrasonic vibration field transmitted through a cracked specimen undergoing an additional low frequency structural vibration. If the specimen is undamaged the two vibration fields do not interact. This technique is a potential non‐destructive testing method. A model is presented which accounts for this phenomenon quantitatively. Using receptance analysis and an Finite Element model, it is shown that the effect is strongly dependent on the carrier ultrasonic frequency and the system damping.