No abstract

The purpose of this paper is to propose a two-step optimization method to design tuned inertial mass dampers for elastic-plastic MDOF structures using the time-frequency dual domain performance evaluation. Although the frequency-domain-based approach allows us to obtain the optimal design independent of the characteristics of disturbances, it cannot consider the elastic-plastic response of structures. On the other hand, the timedomain design is highly dependent on the characteristics of design earthquake ground motions. The proposed two-step method resolves these issues by use of dual-domain information. Finally, the response analysis for recorded ground motions demonstrates the effectiveness of the proposed design method.

Shun NAKATA, Kohei FUJITA and Izuru TAKEWAKI Tuned mass dampers exhibit high performance when optimally tuned to a structure. However, their damping performance decreases once the natural period of the structure is elongated due to the elastic-plastic response under strong earthquakes. In this paper, long-duration earthquake ground motions are substituted by the multi impulse and the optimal characteristics of the tuned inertial mass dampers are derived numerically.This substitution allows us to avoid conducting repetitive computation of complicated and time-consuming nonlinear time-history response analysis. An ideal drift response curve is proposed for structures subjected to multilevel seismic ground motion inputs and an optimal design method is presented.