Excentricidad del centro de gravedad

e_{f} = \frac{ζ_{d} \cdot E_{c, eff} \cdot I_{I} \cdot e_{I} + (1 - ζ_{d}) \cdot E_{c, eff} \cdot I_{II} \cdot e_{II}}{ζ_{d} \cdot E_{c, eff} \cdot I_{I} + (1 - ζ_{d}) \cdot E_{c, eff} \cdot I_{II}}

;