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Please observe the Finite Element model below, in ANSYS WorkBench, (Remote force behavior = Deformable). enter image description here

Also, please take a lot at the force and moment reactions at the fixed supports. enter image description here I couldn't understand that why am I seeing a moment reaction about Y axis at the fixed supports for both of the beams? I mean yes, for the reaction forces to be different from each other, it makes sense mathematically that that the beam which is relatively closer to the applied force will have more portion of that force passing through it. But why do the beams turn a little bit clockwise when the remote force is applied in this manner? And why do they generate a reaction moment at end of each of the beam?

Moreover, I have also conducted an analysis with a simple force passing through the centroid of the same scoped faces with the same value, and it neither generated any reaction moments nor the beams turned clockwise. So the question basically becomes that why would the force when applied somewhat closer to one of the beams would do so?

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  • $\begingroup$ How is your force connected to your beams? Ridigly? If so, I assume the link between the two beams produces the bending? $\endgroup$
    – Öskå
    Oct 6, 2021 at 14:20
  • $\begingroup$ It is written in the first line of the post that the remote force behavior is DEFORMABLE. $\endgroup$
    – Rameez Ul Haq
    Oct 6, 2021 at 14:30
  • $\begingroup$ Unfortunately that doesn't mean much to me, but I'm pretty sure that the behaviour isn't the one you expect. Try the same on APDL where you would actually be sure of what's being done without the boxes. $\endgroup$
    – Öskå
    Oct 6, 2021 at 14:32
  • $\begingroup$ @RameezUlHaq For people who understand FEA and beam bending but don't use Ansys, "Remote force behaviour = deformable" means nothing. The pictures don't explain how the force is actually applied to the beams. $\endgroup$
    – alephzero
    Oct 6, 2021 at 15:54
  • $\begingroup$ Deformable behavior = each of the nodes on each of the scoped faces can move independent of each other. Rigid behavior = each of the nodes (and hence each scoped face) cannot move independent and hence has to move somewhat altogether. I hope this was clear enough. $\endgroup$
    – Rameez Ul Haq
    Oct 6, 2021 at 16:21

1 Answer 1

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Because both beams are loaded in the transverse directions. No matter the magnitude, the transfer loads lead to moments. If you didn't assign the transverse loads, then check your model for geometric irregularities or input mistakes.

enter image description here

Understand the causes of errors in FEM programs:

enter image description here[enter image description here]enter image description here3

See this articlefor more details.

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    $\begingroup$ Why do you think a force of $10^{-3}$N in the X direction is anything more than a rounding error, compared with hundreds of N in the Z direction? $\endgroup$
    – alephzero
    Oct 6, 2021 at 15:55
  • $\begingroup$ I don't know what you mean by transverse, but we usually classify transverse force as the one which is perpendicular to the longitudinal direction. Here, it is not transverse but is an axial or longitudinal force. $\endgroup$
    – Rameez Ul Haq
    Oct 6, 2021 at 16:25
  • $\begingroup$ The axial force is Fz in this case, the rests are transverse forces. $\endgroup$
    – r13
    Oct 6, 2021 at 16:26
  • $\begingroup$ Rounding error in static axial load solutions? Throw that junk out. $\endgroup$
    – r13
    Oct 6, 2021 at 16:29
  • $\begingroup$ So what you are saying is that the as @alephzero mentioned, those extremely small loads along the Y and X axis is causing that moment? I am not even that much of an expert in FEA but still I would call these Numerical Errors which are inherently present in FEA solvers. $\endgroup$
    – Rameez Ul Haq
    Oct 6, 2021 at 16:32

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