Developing Inelastic Jerk Spectra for Pulse-Like Earthquakes

Jerk, or jolt, is defined as the time derivative of acceleration. This study investigates the jerk response of inelastic single-degree-of-freedom (SDOF) systems subjected to pulse-like near-fault ground motions. Compared with ordinary non–pulse-like records, pulse-like motions can impose significantly higher demands on structures. In this work, constant-strength spectra for the jerk response of inelastic SDOF systems are developed using a set of ۹۱ pulse-like earthquakes. The influence of key structural parameters, including strength reduction factor, hysteretic behavior, and viscous damping ratio, is examined. The results show that jerk demands exhibit slightly higher sensitivity to viscous damping in the short, normalized period region than in the long-period region. Furthermore, an analytical equation is proposed to estimate jerk demand as a function of the ratio of elastic vibration period to pulse period and the strength reduction factor, for various hysteretic models and damping ratios.

کلیدواژه ها:

Jerk spectra ، Inelastic systems ، Pulse-like earthquakes ، Strength reduction factor