Estimation of Damping Correction Factors Using Duration Defined by the Standard Deviation of Phase Difference. Issue 2 (May 2015)

• Record Type: Journal Article
• Authors: Nagao, Kenichi; Kanda, Jun
• Is Part Of: Earthquake spectra. Volume 31:Issue 2(2015)
• Page Start: 761
• Page End: 783
• Publication Date: 2015-05
• Subjects: Earthquake engineering -- Periodicals; Earthquake engineering; Periodicals; 624.1762
• DOI: 10.1193/103012EQS321M
• Languages: English
• ISSNs: 8755-2930

Abstract

The damping correction factors (DCFs) to convert the 5% damping acceleration response spectra to those for other damping levels are computed for the records of 13 Japanese earthquakes. Their correlation with the standard deviation of phase difference ( σ ) is also investigated in ten frequency bands. The σ -DCF relations obtained are found to be very similar across the different types of earthquakes. Further, regression analysis suggests that for damping ratios of 1% and 2%, with the increase in σ, the DCFs increase in low-frequency bands (up to 4–5 Hz), whereas they decrease in higher frequency bands. On the other hand, for damping ratios of more than 5%, with the increase in σ, the DCFs decrease in low-frequency bands (up to 1 Hz), whereas the opposite tendency is observed in higher frequency ranges. This research also discusses the applicability of the σ -DCF relations to design ground motion simulation.