| Applies To | |||
| Product(s): | AutoPIPE | ||
| Version(s): | 2004, XM, V8i | ||
| Area: | combinations | ||
| Original Author: | Bentley Technical Support Group | ||
| Date Logged & Current Version | May 2015 09.06.02.06 |
Problem:
What is the M/S column in AutoPIPE's output reports?
Solution:
Depending on this setting it describes at what level the calculations are to be analyzed, i.e. at the Moment level (M) or at the Stress level (S). See AutoPIPE help for details on this setting.
M means that the individual moments of the load cases are combined (via the selected combination method), and the result is applied to the stress equation dictated by the code. If the user selects S, the load cases are solved using the stress equation individually, and the results are then combined using the selected combination method.
For example, if we have moments for load case 1 and load case 2 (M1 and M2, respectively) and wish to evaluate B31.1 Sustained load equation:
By using the same moments, but selecting S this time:
where
Basic load cases (GR[1], T1[1] etc.) cannot be combined at stress level and would always be set at moment level. Components which already has a stress value calculated (like other code combinations e.g. SL1 and SL2 in example above, or category maximums like (SUS), (EXP) or special cases like pressure stress indicators like (LONG) or (HOOP)) can be combined at stress level.
Having elements with S as well as M in the same combination is allowed and you can see that in almost all Occasional code combinations, where the (SUS) is at stress level and the occasional load case would be at moment level.
Again, Moments are evaluated for each load individually prior to combinations. Also, the Young's modulus for each respective load should be used in when combining load case in your User combinations.