Stresses versus steel verification

The image below shows the tensile stress and the steel verification for 3 different beams:

• For Beam 1: based on the stresses, you’d expect a steel verification of 100%. But the steel verification is lower.
  This is because Diamonds shows the elastic stresses (calculated with W_el), while this section is of class 1 and thus plastic properties (W_pl > W_el) will be used in the steel verification.
• For Beam 2: based on the stresses, you’d expect a steel verification of 100%. And indeed, the steel verification is 100%.
  This is because Diamonds shows the elastic stresses and this section is of class 3 (W_el) will be used in the steel verification.
• For Beam 3: based on the stresses, you’d expect a steel verification of 100%, but the steel verification is higher.
  This is because Diamonds shows the elastic stresses (calculated with W_el), while this section is of class 4 and thus effective properties (W_eff < W_el) will be used in the steel verification.

So, it is important to do a steel verification because:

• the stresses shown in the global window in Diamonds, are stresses caused by axial force and bending around the z’ OR y’-axis.
  It neglects shear, torsion, the risk of instabilities and combinated forces (like N + V + M or N + M + M).
• Diamonds shows elastic stresses.

Note: it is not possible to show the stresses according to the Von mises criterium in Diamonds.