Definition - What does Acoustic Emission mean?
Acoustic emission refers to the sound waves that are generated when a certain material goes through internal change or stress brought about by external forces. It is a phenomenon that takes place in processes such as mechanical loading, producing elastic waves.
The waves produced are captured to study and be used for quality control, corrosion monitoring and system feedback.
Corrosionpedia explains Acoustic Emission
Acoustic emission is referred to as the passing elastic waves in a material produced through the release of stress energy in a local area. Thus, the event source is described as the phenomenon that discharges elastic energy in the material that disseminates as elastic waves.
Acoustic emission testing is mainly applied in the following areas:
- Determination of source location where events occurred
- Characterization and evaluation of mechanical performance of material
- Monitoring safety operations of structures like pipelines, pressure containers and bridges
Acoustic emission can be associated with the irreversible energy release which can be produced from sources that do not involve failure, such as impact, friction and cavitation.
This technique has been very useful in the analysis of crack formation and welding processes. A material that is situated in active stress like airplane components and transducers mounted in a particular area can identify crack formation before it starts propagating. This process has also been widely applied in process monitoring such as identifying batch granulation irregularities and fluidized bed anomalies.