Abstract
Custom made electrostatic transducers were used for ultrasonic investigations of damaged CFRP. These investigations resulted in identification of non-linear ultrasonic responses due to the presence of damage. The broadband nature of electrostatic transducers is essential for this work to scan a wide range of frequencies to identify non-linear responses. These non-linear response frequencies were used with an electrostatic transducer to induce thermosonic heating at the damage which was measured with an IR camera. The use of non-linear response frequencies reduces the power required to produce thermosonic heating. Travelling guided waves (Lamb waves) allow excitation of the damage at a distance from the excitation source allowing large samples to be studied. This provides a completely non-contact measurement for NDE which shows promise for future composite inspection systems.