Abstract
Ductility has been a popular damage measuring index, though it fails to account for the role played by repeated inelastic excursions of different amplitudes. A typical earthquake response time history is characterized by the repetitive cycles with different orders of peaks. In such a case, damage not only depends on the maximum response and its magnitude beyond the yield level but also on the higher order peaks. Thus, the additional parameters of interest are the total number of peaks, and the number as well as the extent of non-linear excursions. To obtain the expected damage corresponding to a response process, a model has been considered which includes the uncertainties both in terms of the amplitudes of the peaks and of their ordered occurences. Under the assumption of a narrow-banded response, the effects of the system parameters and the response duration on damage and ductility have been studied.
