The characteristic yield strength of steel used in EC3 (EN 1993) design is based on table 3.1 of the code.  Design resistances are obtained by dividing the characteristic value of a particular resistance by the global partial safety factor for the resistance, γ_m. The magnitude of γ_m is based on Cl. 6.1 of EN 1993-1-1:2005 and can change depending on the selected National Annex.

Material coefficients for steel in STAAD.Pro take the following default values unless replaced by user’s numerical values provided in the input file.

• Modulus of Elasticity, E = 205,000 N/mm²
• Shear Modulus, G = E/2(1+ ν)
• Poisson’s Ratio, ν = 0.3
• Unit weight, Γ = 76.8 KN/m³

The magnitude of design loads is dependent on γ_f, the partial safety factor for the action under consideration. You are allowed total control in providing applicable values for the factors and their use in various load combinations.