Capacity of structural ductility reduction factor is used for estimating inelastic deformations that may develop in severe earthquakes.It is not only the key factor in the current building codes to estimate strength demands for seismic-force-resisting systems

but also the key parameters to determine the equal-ductility inelastic response spectra in performance-based seismic design.In this paper

17 RC frame buildings with different fortification intensities and storeys are designed according to the current Chinese Codes.These structures are modeled and analyzed in the platform OpenSees.By comparison of the quasi-static test data with calculated data for RC frame structures

the OpenSees models are verified and validated.By comparison of seismic response of elastic and inelastic structural systems

the values of capacity of structural ductility reduction factors and their variation rules with structural storeys and design fortification intensities are analyzed and derived.It is shown that structural inelastic energy dissipation capacity under strong earthquake can be quantitatively estimated by the value of capacity of structural ductility reduction factor.For RC frames designed in seismic fortification intensity VI

VII and VIII

structural ductility reduction factors capacity are 3.7、3.5and 3.2respectively.