2011 Volume 67 Issue 2 Pages I_801-I_812
In this study, estimation equations of maximum response ductility from the acceleration response of a nonlinear SDOF system during an earthquake are proposed. It is assumed that the model has a bilinear skelton curve and is subject to Masing's law. The estimation equations are the function of the equivalent natural period and damping ratio on the assumption that the nonlinear system is approximated with an equivalent linear model. The approximation is conducted in the time and frequency domains, respectively, and different estimation equations are derived for each domain. The validity of the proposed equations is confirmed through the numerical simulations. It is found that the equations derived in the frequency domain have higher accuracy if extracted acceleration records with impulsive response are used. It is also found that the equations derived in the time domain give bad accuracy when the displacement response is nonsymmetric or acceleration records contain measurement noise.
