# yade-users team mailing list archive

## Re: [Question #696047]: calculation of flexural stress in 2D condition

```Question #696047 on Yade changed:

Karol Brzezinski proposed the following answer:
Hi,

sorry, forget the second part. It would be good for the statically
indeterminate beam. Since you have a four-point bending test, you know

Regarding the first part, I meant that in actual 2D formulation you do
not have to worry about thickness.

The load that you obtain (apply?) in the simulation has a force dimension, thus I think it is related to some thickness. Whatever thickness you assume, you should treat the force as integral over this thickness. For example, if your sample has b = 40 mm, and your model has b' = 1 mm, you should apply only f'=f*b'/b = f/40.
In general, b' doesn't have to correspond to the thickness of your sample, you could also assume b'=b. This would mean that your sample is 'compressed' to the thickness of the model. In such a case, however, the stiffness considerations become harder.

In my opinion, assuming thickness to solve this problem is quite
intuitive, and could be a good solution in some cases. However, it is
probably oversimplified. It would be useful to know the purpose of the
simulation and what is the advantage of using DEM? Is this advantage
affected by the 2D assumption?

Besides all that 'fundamental questions', I think that both solutions
proposed by you are quite decent (if you stick to 2D simulation ;) ).
Only, remember to apply the force corresponding to the assumed
thickness.

Cheers,
Karol

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