Understanding Acoustic Emission Testing- Reading 1 Part B-A

Knowledge of the Kaiser Effect and Felicity Effect can be used to determine if
major structural defects are present. This can be achieved by applying
constant loads (relative to the design loads exerted on the material) and
“listening” to see if emissions continue to occur while the load is held. As
shown in the figure, if AE signals continue to be detected during the holding
of these loads (GH), it is likely that substantial structural defects are present.
In addition, a material may contain critical defects if an identical load is
reapplied and AE signals continue to be detected. Another guideline
governing AE’s is the Dunegan corollary, which states that if acoustic
emissions are observed prior to a previous maximum load, some type of new
damage must have occurred. (Note: Time dependent processes like corrosion
and hydrogen embrittlement tend to render the Kaiser Effect useless)
Dict:
Corollary: something that results from something else.
Charlie Chong/ Fion Zhang