Constant-damage residual ratios of SDOF systems subjected to pulse type ground motions

Residual displacement is an important index to quantify postearthquake structural performance, as it provides information about the structure reparability and its structural performance during aftershocks. This manuscript presents the results of a statistical study into residual ratio, i.e. the ratio of the residual displacement to the maximum inelastic displacement, for single degree of freedom (SDOF) systems with constant damage performance under 71 nearsource pulse type ground motions. The effects of seismic and modeling parameters such as the peak ground acceleration to peak ground velocity ratios (AP/VP), hysteretic model, ultimate ductility capacity and strain hardening ratio on residual ratios are also evaluated. The results indicate that the residual ratios in the whole range of periods are strongly dependent on the damage index, DI, and mean residual ratios increase with the increase of damage index, DI. The findings clarify that the residual ratios are significantly influenced by the AP/VP. Additionally, they show that the hysteretic model of SDOF systems and strain hardening ratio have more obvious effects on the residual ratios than the ultimate ductility capacity.