Generating Artificial Earthquake Wave Compatible with High-damping Target Spectra

Abstract

This paper presents a new method of generating the time-history waveforms which are compatible with multiple-damping design spectra. To assess the structural integrity of buildings and reactor buildings, time-history response analyses are conducted using artificial seismic waves which are matched with the target design spectra. The damping factors of artificial seismic waves are defined as approximately from 0.01 to 0.05. These damping factors differ from damping factors applied to seismically isolated buildings because the seismically isolated buildings use the damping forces corresponding to the damping factors of approximately 0.2 to 0.4. The time-history waveforms which are matched with the design target spectrum with damping factor of 0.05 can lead to large variations in the seismic responses for the seismically isolated buildings. The iteration schemes to suppress the large variations in the seismic responses have been developed by employing the correction waveforms. However, these iteration schemes which are capable of being applied to structures with high damping factors, such as the seismically isolated buildings, have not been developed yet. This is because the frequency intervals of the correction waveforms significantly affect the convergence to the target design spectra with the increasing damping factor. Therefore, this paper presents a new type of method focused on the frequency intervals of the correction waveforms and demonstrates the effectiveness of this method by generating the time-history waveforms which are compatible with multiple-damping design spectra including the high-damping factors.