How to verify the beam moment and stress calculation?

To verify that, we have modeled a simply supported beam of a length of 10 m with a rectangular cross-section of 1x1 m.

Further, 10 kN/m uniform load was applied to the beam. Now, the stresses were observed only due to bending. 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 N*mm or 125 kNm.

where, Z = bd^2/6

According to Midas software, the moment at center is 125 kN*m itself as shown below.

Kindly find the attached verification model