Acoustic emission (AE) method

Acoustic emission (AE) is elastic radiation generated by the rapid release of energy from inside the material. These elastic waves are detected and converted to electrical signals by piezoelectric transducers bonded to the material surface. Fracture, impact, corrosive film rupture and other similar deformation processes may cause acoustic emission. Acoustic emission is fairly sensitive to detect newly formed crack surfaces of micron level. AE is a proven and reliable structural health monitoring tool for predictive maintenance and detects the cracks and damages well before they may endanger the well being of the structure.

Acousto-ultrasonics (AU)

Acousto-ultrasonics uses pulser and receivers with resonant frequencies in low ultrasonic range to detect damages. Ultrasonic waves are reflected by surfaces and interfaces, attenuated by dispersion and absorption and undergo mode changes during reflection and transmission. The technique is able to detect and characterize differences in the structure of single and multilayer metallic and composite structures. When damage has occurred to a structure, changes in the signal indicate the type of damage.