Non-iterative equivalent linearization method for generating seismic fragility curve of equipment

Abstract

In the seismic PRA, tremendous computational and human resources are required to evaluate the seismic fragility curves of facilities in a nuclear building, so the development of a simple evaluation method has been desired. In this study, we propose and apply a non-iterative equivalent linearization method for evaluating the real capacity (median value of fragility curve) and propose a method that can easily evaluation seismic fragility curves. Then, the method was tested using 6 equivalent linearization models for equipment installed on the ground surface and comparing the results with those obtained using nonlinear analysis. The validation was done by using 37 ground motion records observed by Japan Meteorological Agency. As a result, the equivalent linearization method proposed by Liu et al. (2015) and Watabe et al (1985) can obtain relatively stable results. In particular, the equivalent linearization method of Liu et al. was found to be independent of parameter changes.