Cracked/Uncracked Stiffness

Users may take into account the effect of cracking during the linear analyses, i.e. Eigenvalue and Response Spectrum analyses, by selecting to use sections with cracked stiffness. The cracked stiffness may be defined as a percentage of the corresponding uncracked stiffness, or, in the case of unelastic frame elements only, from the section’s M_y/θ_y (bending moment at yield/chord rotation capacity at yield) ratio. In the latter case, users should select the employed Code for the calculation of the chord rotation capacity at yield.