Bending Moment Resistance Calculation for Beams and Columns without FRP application

[Daniele.arcuri]

Dear FRP Designer support,

I would like to ask a couple of questions regarding the calculation of bending moment resistance for both beams and columns before the FRP reinforcement application. Specifically, when dealing with columns, after entering the steel and concrete strength values and their respective averages in the material properties, I obtain a certain bending moment value. Nevertheless, when I modify the \alphacc parameter (from 0.85 to 1) and the confidence factor (for example from 1, which is the default, to 1.2) in the settings, the bending moment value remains exactly the same.

Additionally, always for what regards columns, increasing the axial force does not result in an increase in the bending moment.
I would appreciate an explanation regarding thee issues. Furthermore, if possible, I would like to request a validation report for the bending moment calculation. Are the equations reported in Biskinis and Fardis (2009) considered for the calculation of the capacity of rectangular sections?

Thank you for your kind attention, and I look forward to your response.

Kind regards,
Arcuri Daniele

[z.gronti]

Dear Daniele.arcuri,

The parameters you modify will affect the section's bending moment, provided that no steel rupture failure occurs. If a steel rupture failure does occur, these modifications will not impact the section's bending moment.
Yes, the equations reported in the D. Biskinis and M. N. Fardis (2009) have been implemented for the calculation of the bending moment of the existing member.