Crack length
Crack length
(OP)
What methods are available for measuring the change in length of a crack, or for that matter if the crack is growing? The crack itself is normally inaccessible without major dismantling although the crack opening at the surface can be seen.
Is it also possible to determine the age of a crack?
Is it also possible to determine the age of a crack?





RE: Crack length
The age of a crack can sometimes be determined depending on the environment or the growth mechanism. If it is a fatigue crack some estimate can be made via the striation pattern, if it is in a corrosive environment the thickness of the corrosion product can be used and I have seen forensic data presented using the types of pollen trapped in the surface to determine the age of a crack.
RE: Crack length
RE: Crack length
RE: Crack length
RE: Crack length
RE: Crack length
Maui
RE: Crack length
RE: Crack length
RE: Crack length
Have you considered radiography?
RE: Crack length
RE: Crack length
I would agree that ultrasonic inspection in the hands of a good operator is generally the best technique so long as the casting has been heat treated correctly and therefore does not attenuate the sound excessively.