A significant minority of the users over at the /r/SpaceX Reddit community seem to be of the opinion that SpaceX will attempt to reuse the Falcon 9 CRS-5 first stage provided it lands on the downrange barge successfully. I disagree, and believe that it's likely SpaceX will thoroughly examine and analyze the returned stage, whether that be through destructive or nondestructive testing.
In particular, I am led to believe that they will put significant focus on the engines, the turbopumps, and the tankage structure. Elon Musk has mentioned on a previous launch abort where they didn't see expected thrust rampup that they took Falcon 9 down and "boroscoped" the engines.
My question is, what mechanisms and tests will SpaceX likely employ to understand the stresses and fatigues that the first stage undergoes? Will these tests be destructive? Does anyone have examples of tests commonly employed in the aerospace industry to check for fatigue, etc?
If the answer to the second question is a "no", would it be a good idea to look at reuse of the CRS-5 stage?