[BUG] EN 1993-1-2 4.2.3.5 verification, µ-factors

[TimoKet]

Robot calculation note does not show the values for µ-factors, but by reverse calculating them from results it seems like Robot uses EN 1993-1-2 formulas for them. In 2009 corrigendum AC:2009 the formulas have been changed

EN 1993-1-2 (2005)

EN 1993-1-2 AC (2009)

Example

By calculating from Robot calculation notes we get µ_y = -2.29

Now if we insert values to equations we get

Small difference (-2.29 and -2.27) may occur from roundings, but value is clearly closer to the wrong value.

[TimoKet]

Bump

[okapawal]

@TimoKet 

Let me consult it with the development team.