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Distinguished Contributor
madg1
Posts: 108
Registered: ‎03-16-2012

Results Interpretation

210 Views, 5 Replies
04-02-2013 10:30 AM

hi

 

can any one help decipher this warning? you help is appreciated. thanks

 

 

 

Reaction Sums and Maxima for Load Case 1

Sum of applied forces
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
-1.3310E+03 1.9263E+02 -2.6435E+05 -4.8379E-04 -4.4756E-04 -1.6871E-04

Sum of reactions
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
1.4116E-03 -3.2967E-04 2.4367E-04 4.9313E-04 2.2426E-03 6.4652E-05

Sum of residuals
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
-1.3310E+03 1.9262E+02 -2.6435E+05 9.3428E-06 1.7951E-03 -1.0406E-04

Sum of unfixed direction residuals
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
1.1283E-02 4.7994E-04 -7.4321E-04 9.3428E-06 1.7951E-03 -1.0406E-04

Largest applied forces and moments
Node Node Node Node Node Node
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
400698 104274 400263 276492 104640 104640
-2.3963E+03 4.7155E+03 -3.8027E+05 -1.4074E-03 -1.4566E-03 -1.1498E-03

Largest nodal reactions
Node Node Node Node Node Node
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
1513 1513 400263 276492 104640 104640
-9.6575E+03 1.0429E+04 3.8027E+05 1.4074E-03 1.4567E-03 1.1499E-03

Largest nodal residuals
Node Node Node Node Node Node
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
1513 1513 23859 274561 131245 225395
-9.6575E+03 1.0429E+04 2.9406E+03 -1.5342E-05 8.5274E-04 4.8354E-04

Largest unfixed direction residuals
Node Node Node Node Node Node
X-Force Y-Force Z-Force X-Moment Y-Moment Z-Moment
131245 152450 131188 274561 131245 225395
6.3964E-03 1.0447E-03 -1.9315E-04 -1.5342E-05 8.5274E-04 4.8354E-04

madg1
ASIMM 2012
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Distinguished Contributor
madg1
Posts: 108
Registered: ‎03-16-2012

Re: Results Interpretation

04-02-2013 10:48 AM in reply to: madg1

madg1
ASIMM 2012
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Valued Mentor
AstroJohnPE
Posts: 504
Registered: ‎08-30-2012

Re: Results Interpretation

04-02-2013 05:57 PM in reply to: madg1

I don't see a warning or error, so perhaps you just want a description of the output. (By the way, this text comes from the Summary file that can be viewed in the Report environment.)

 

  • The "applied forces", "reactions", and "residuals" are the same as the "Results Contours > Other Results > Reactions > Applied Force", "Internal Force", and "Reaction Force (Negative)" that can be viewed in the Results environment.
  • Hopefully it is obvious that the "sum of" is the sum of the results at each node, broken into each of the 6 directions.
  • The "unfixed direction" results are an indication of a problem in the solution. If any of the unfixed directions are nonzero, it indicates that some of the applied loads are "leaking" out of the model; that is, some of the load is not going to the ground through any of the constraints.

In my opinion, the only rows of interest are "residuals" so that you can confirm the load applied is what you think it is, and "unfixed directions" which would indicate a solution problem.

 

Let us know if you have any other questions.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

16 years experience with Simulation Mechanical
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Distinguished Contributor
madg1
Posts: 108
Registered: ‎03-16-2012

Re: Results Interpretation

04-02-2013 06:06 PM in reply to: madg1

thank you john for the reply.

 

so the sum of applied forces and sum of reactions need not be equal?

 

I am using surface contact in linear analysis? do you think that my be the reason for my leakage?

 

madg1
ASIMM 2012
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Valued Mentor
AstroJohnPE
Posts: 504
Registered: ‎08-30-2012

Re: Results Interpretation

04-03-2013 05:29 AM in reply to: madg1

Once again, the "sum of reactions" in the list is not the reaction forces and moments that we engineers work with. I have never gotten a clear understanding of the "sum of reactions" in the list other than it is something of interest to the Ph.D. F.E.A. programmers. What we engineers call the reaction forces is the item "sum of residuals" in the list, except the "sum of residuals" is not the reaction force on the model but the reaction force on the environment. (Techinically speaking, "sum of residuals" = "sum of applied loads" + or - "sum of reactions", if that helps your understanding.)

 

What I see in your model is that the engineering reaction forces ("sum of residuals") equals the applied loads ("sum of applied forces"). This is the correct answer. Also, the "unfixed directional residuals" are very small, especially compared to the single largest applied load (6E-3 versus 4.7E+3), so I do not see any evidence of applied loads leaking out of the model. What result are you looking at that makes you think some of your applied loads are not going into the supports?

 

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

16 years experience with Simulation Mechanical
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Distinguished Contributor
madg1
Posts: 108
Registered: ‎03-16-2012

Re: Results Interpretation

04-03-2013 09:43 AM in reply to: AstroJohnPE

okay.I made that leaking statement before i noticed negative powers.:smileyhappy:

 

Anyway Thank you very much john. 

madg1
ASIMM 2012
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