Beam Moment Vs. beam Stress

Question:

Good morning,

I'm wondering about how the beam moment results are calculated, as the results given by the beam moment output dont seem to match the results if I take the stress and back calculate the moment.



Answer:

Hello,
Greetings.

Thanks for reaching us.
To verify that, I modeled a simple supported beam of length of 10 m. Beam was a rectangular section of 1x1 m.


Further, 10 kN/m uniform load was applied to the beam.
Now, the stresses were observed only due to bending stresses. The stress at top and bottom were -7.5 N/mm2 and 7.5 N/mm2 respectively.



Now, due to this stress, M= Stress * Z  = 0.75 * (1000*1000^2 / 6) = 125 *10 ^ 6 Nmm or 125 kNm.
where, Z = bd^2/6
According to midas software, the moment at centre is 125 kNm itself as shown below.


Hope this explains.
The midas model file is attached for review.
Creation date: 6/8/2021 2:06 PM      Updated: 6/8/2021 2:06 PM
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Beam moment vs beam stresses.mcb
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