Understanding Acoustic Emission Testing- Reading 1 Part B-A

Acoustic emissions, which occur in most materials, are caused by irreversible
changes, such as
(1) dislocation movement,
(2) twinning,
(3) phase transformations,
(4) crack initiation, and propagation,
(5) debonding between continuous and dispersed phases in composite
materials, and so on.
In concrete, since the first three of these mechanisms do not occur, acoustic
emission is due primarily to:
1. Cracking processes
2. Slip between concrete and steel reinforcement
3. Fracture or debonding of fibers in fiber-reinforced concrete
Charlie Chong/ Fion Zhang