Applies To
Product(s):	AutoPIPE
Version(s):	ALL;
Area:
Date Logged & Current Version	Oct. 2017 11.01.00.23

Problem:

Why are the results for ASME NB 2015 eq.13 different than were in previous code years, 2007-2013?

Example:

Ran the same model with all previous codes years back to 2007 and the EQ. 13 stresses are the same and are shown to meet those code year allowables. It appears that for the 2015 code year, the EQ. 13 calculated stress is not using the correct stress index, C3', and are shown to exceed allowables.

Why?

Solution:

Note that there were changes to the code in 2015 that may lead to a difference in results than reported by previous code years. For example, you can see a different in Table NB-3681(a)-1, C3 & C3'.

Also note, equation 13 is not the same between 2015 and previous years. Definition for Mi have changed and would cause different output results between the indicated code years. Suggest to review the code definitions as one refers to moments from equation #9, while the other code references moment definitions from equation #10.

in addition, the temperature term along side of the C3 & C'3 may be zero and that would explain the same stress result for both Eq. 10 & Eq. 13, with both having the same load pair.

Q. Eq 13, why are the results different between different code years when using AutoPIPE?

Problem:

Solution:

See Also