Research on inelastic energy absorption factors for equipment in nuclear power plant buildings

Abstract

In this study, inelastic energy absorption factors are investigated for the equipment installed in the nuclear building. The elastic-plastic response spectra were evaluated using synthesized base layer wave of the Japan Building Center of Japan, BCJ-L1 and BCJ-L2, and actual observed seismic ground motions, and the inelastic energy absorption factors were calculated and compared. As a result, it was found that the inelastic energy absorption factors tended to be underestimated for equipment with a period longer than the building's natural period and overestimated for equipment with a shorter period. It was also found that the factors varied greatly depending on the type of seismic ground motion used in the calculation, although the overall trend did not change much when the installation position or the second stiffness of bi-linear restoring force of the equipment were changed. Therefore, that there are some issues in the calculation of inelastic energy absorption factors based on the energy conservation because it varies depending on the seismic ground motion.