ASTM E399: Plane-Strain Toughness for Materials Testing

[hootsh]

Hi, I hate the fact that my first post in forum is all about wanting not giving, but I'm only at 1st year mechanical so I don't think there'e much to give :DI was wondering about E399 in the ASTM standard, according to this video (last minute):

http://www.youtube.com/watch?v=WlFs2unBvdU

We have to have thick specimens in order to properly measure plane-strain toughness, but they use small thickness in the experiment.

Also is there any website or material where I can find the simplification or summarization of these ASTM standards? The way they explain these tests is a bit too complicated and massively messy for a student like me, really poor documentation in my opinion, but maybe its because I'm new at this.

Thanks in advance. :)

 

[Unrest]

How thick is thick?

ASTM E399: " the crack-tip plastic zone is small compared to the crack size, specimen thickness, and ligament ahead of the crack."

So for a brittle material with a small plastic zone, the specimen may appear to be a thin plate rather than a cube-shaped block and still be considered "thick".

 

[hootsh]

Oh, it actually says that in the experiment?

How could I have missed that xD ?

Thanks a lot for the help mate.