Sensitivity analysis of yield level for seismic response of elastoplastic structure.

Abstract

From the past research, it is known that the maximum rms relative displacement of an elastoplastic structure subjected to a nonstationary input has a minimum value at an appropriate yielding level owing to the energy absorption. In order to obtain the optimal yielding level, this paper presents a sensitivity analysis of the yielding level for the seismic response of elasto plastic structures. Herein the sensitivity analysis is to find the sensitivity coefficient of the yielding level to the maximum rms relative displacement. By using these sensitivity coefficients, the probability distribution of the rms relative displacement can be evaluated from that of the yielding level of the structure. The seismic response of the structure was studied assuming that the restoring force characteristics of structure are represented by a simplified Clough model with the stiffness degradation, and the covariance of responses were computed by using an equivalent linearization technique on the assumption of narrow band response. The theoretical results were compared with those of digital computer simulation.