Brittle crack growth in normally ductile materials

[C0rnNutts]

Hey guys,
I'm new here so please be easy on me if I break any "unwritten" rules.
I'm doing a design study on brittle crack growth in ductile materials. As I understand it, when a macroscopic crack is found in a load bearing plate, holes can be drilled at each end to reduce the internal stresses at the crack tips and therefor arrest the growth. My question is: Does anyone know of a specific instance where this method was used to prevent failure and increase service life? Alternatively, an instance where this method could have been used to prevent a failure but was not?
Thanks in advance!

 

[jim hardy]

Does anyone know of a specific instance where this method was used to prevent failure and increase service life?

We hillbillies do it all the time on our shovels and tractor fenders.

An industrial example is mentioned around page six here:

http://pbadupws.nrc.gov/docs/ML0134/ML013400370.pdf

about page 22 is a formula for stress concentration around an elliptical crack arresting hole.
Surely a search engine will take you places.. just have to feed it the right keywords. Maybe that report will help you with vocabulary.

 

[etudiant]

Drilling a hole to arrest a crack is almost routine in aircraft maintenance.
Usually the specifications allow for small failures, but larger ongoing breaks are taboo. Do note that there are procedures to ensure that this does not cause additional problems.