Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers about AutoPIPE's Forces & Moments Output report : Items #1, Question: At a pipe end point, actually a weld neck flange (A00), I have added concentrated forces (and moments) and made it an anchor point. When I list the results for Restraint Reactions the concentrated forces are included, but when I list the results for Global Forces & Moments in the same point they are excluded. I was expecting to see the same values but with opposite signs. Can anyone explain? Answer: The Forces and Moments and Restraint (anchor) reports may not always agree, each report maybe looking at a different side of the cutting plane. In AutoPIPE, Pipe forces and moments are reported at one side of the cutting plane at a point. We remove all piping from the beginning of the segment up to the point and we look at what's left of the cut. Forces acting at a point would appear in one cutting plane, but not the other. See the following online help section: Help Contents reference information results interpretation Pipe Forces and Moments: Global Option for more information. This is a limitation of reporting one side of the cutting plane for pipe points. In AutoPIPE XM and higher we have a new Reference Point report that allows you to report forces at any side of the point you wish In addition: Support Report Creates a section which lists support forces and displacements (local, and global) for each active load case and Other combination. Restraint Report: Creates a section which lists anchor and support forces (and moments) at restrained points for each active load case and Other combination. Also, please see the following AutoPIPE help section: Help Contents Contents Reference Information Results Interpretation : Support Forces: Hangers and V-stops Support Deformations: Hangers and V-stops without Gaps Support Forces for Guides and Line Stops without Gaps Support Forces: Guides & Line Stops with Gaps & Friction Item #2, Question: The results from the following 3 reports (Restraint, Global Force & Moments, and Reference) are all the same but when a flange is added they are different. Given the following arrangement: R E S T R A I N T R E A C T I O N S Point Load FORCES (N ) name combination X Y Z Result ------ ----------------------- ------ ------ ------ ------ A00 Anchor Tag No.: None Gravity{1} -160 -1024 127 1044 G L O B A L F O R C E S & M O M E N T S Point Load FORCES (N ) name combination X Y Z Result ------ ---------------------- ------ ------ ------ ------ *** Segment A begin *** Line # 250VM-41676-FA01 A00 Gravity{1} 160 1024 -754 1282 R E F E R E N C E P O I N T L O A D S Load FORCES (N ) Combination Actual Allow. Ratio ---------------------- -------- -------- ------ Tag No.: None Ref. ID: A00-1 After A00, Seg A, loads applied towards A00] Gravity{1} FX -160 5500 0.03 FY -1024 5500 0.19 FZ 754 2850 0.26 FR 1282 None Problem: Restraint reaction does not equal the Global Forces & Moments report and Reference Point Load report, why. Answer : As can be clearly see the Reference Point Load and Force s & Moments report the same value. No issue. The only issue of concern, why the Restraint loads do not match the other reports. The answer is because the flange weight has been added to the anchor point and not the pipe, 754 N - 127 N = 627 N (weight of flange + bolting). (42.64 kg flange + 21.32 kg bolt) x 9.81 = 627 N If you expect the pipe to take the flange weight, please insert a new node point a short distance offset from the anchor and move the flange to the new node point instead of placing it exactly on the anchor. Now all 3 reports will match. Item #3, Question: I thought I had a grasp of what was going on with the reactions/forces results tab, but I now seem to be confused again. Please find the attached and let me know if you can clear it up. If I wanted to run a separate analysis on that tee (nodes E01, E02, E03, and R02), I would want to apply the observed forces and moments to the faces to recreate the loading. I have tried following the help file convention but seem to be confused on which of the values read from the chart should be taken as their correct value, or if I need to negate what is shown. Specifically, I am applying the loads from E01, E03, and R02. Answer: AutoPIPE Forces and Moments report displays the pipe internal forces and moments caused by the applied loads. To be able to recreate the loading scenario on the Tee, you would need to apply the forces and moments in the direction opposite to the internal forces and moments displayed in the output report. Considering gravity load case only for the tee point E02: Forces and Moments to be applied (Global) Also, find attached a document trying to explain the same - here See Also Bentley AutoPIPE External Links Bentley Technical Support KnowledgeBase Bentley LEARN Server Comments or Corrections? Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to the "Comments" area below. THANK YOU!
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