Improved damping reduction factor models for different response spectra

The rationality and reliability of the damping reduction factor are of great significance to the seismic design of building structures. However, the values of damping reduction factor predicted by the existing models have great dispersions, which are mainly related to the regression model and the considered influencing factors. Based on the linear time history analysis of a single-degree-of-freedom system under 4716 ground motions, the influence degrees of the damping ratio, the natural vibration period, the ratio between the ground predominant period and the natural vibration period, the earthquake magnitude, the rupture distance, the site type (the average shear wave velocity in the top 30 m of soil), the significant duration, and the peak ground velocity to acceleration ratio (PGV/PGA) on the damping reduction factor are evaluated by the Spearman rank correlation coefficient. After that, improved damping reduction factor models are respectively proposed for different response spectra, in which only the damping ratio and the natural vibration period are considered as variables. Through the comparison with the existing damping reduction factor models and the robustness test under different natural ground motions, the improved damping reduction factor models are proved to have a reasonable expression form and strong robustness, which can accurately predict the damping reduction factors for different response spectra.