The curvature for both crack states c (cracked/uncracked) is calculated as follows:
The strain for both crack states is determined as follows:
Thus, it is possible to determine the mean strain.
The mean curvature is determined as follows:
With the mean curvature and the longitudinal strain, you can calculate the final cross-section properties while taking account of shrinkage, creep, and tension stiffening.
Ideal cross-section area
Ideal moment of inertia to the ideal center of the cross-section
Eccentricity of centroid
Ideal moment of inertia to the geometric center of the cross-section
Poisson's ratio is determined as follows: