8. Acoustic emission control

8.1 Features

Acoustic Emission (AE) is the release of energy in the form of transient elastic waves within a material under load (figure 12 ).

Detection and analysis of the signals provide unprecedented information on stress field anomalies, such as the presence of defects. Detection is performed by a piezoelectric sensor with a frequency of 50 kHz to 1 MHz (generally 50 to 500 kHz).

Acoustic emission differs from conventional non-destructive testing techniques for several reasons:

• the material...