reference/textbook for theory behind VIII-1 impact testing exemptions
reference/textbook for theory behind VIII-1 impact testing exemptions
(OP)
I'm curious about the theory behind the impact testing exemptions permitted in VIII-1. Specifically:
1. Why are thin plates exempt to lower temperatures than thick plates?
2. Why is the effective thickness of plate stress in bending one-quarter of the actual thickness when determining the minimum impact exemption temperature?
Can both of the above questions be answered with classic fracture mechanics theory?
Can anyone point me to a reference textbook or white paper(s) that explains the theory behind these rules?
1. Why are thin plates exempt to lower temperatures than thick plates?
2. Why is the effective thickness of plate stress in bending one-quarter of the actual thickness when determining the minimum impact exemption temperature?
Can both of the above questions be answered with classic fracture mechanics theory?
Can anyone point me to a reference textbook or white paper(s) that explains the theory behind these rules?





RE: reference/textbook for theory behind VIII-1 impact testing exemptions
On your question, toughness is not actually a material property as it can vary based on thickness. Thick components tend to have higher constraint than thinner components and are more susceptible to fracture. Corten's paper uses a 1/4 thickness flaw depth to develop the exemption curves, so the postulated flaws used in the fracture mechanics assessment are larger for thicker plates.
RE: reference/textbook for theory behind VIII-1 impact testing exemptions