Efficient strong motion duration of pulse‐like records for nonlinear structural analyses

Abstract

SUMMARY The special interest produced by near‐field directivity records and their effect on structural response has given a new significance in the velocity time history, its pulse‐like content, and relevant parameters and indices. Recent research has shown that directivity pulses inherent in these records govern the linear and the nonlinear response of a wide range of structures. Based on this observation, it is suggested in this paper that a truncated ground motion, limited to the duration of the predominant velocity pulse, can be efficiently used to predict the structural response, instead of the base motion with the total duration, reducing significantly the required runtimes. The proposed methodology is verified for a series of medium to high rise reinforced concrete buildings, for which nonlinear time‐history analyses are performed for a vast suite of pulse‐like near‐field records applied as base excitations with their total duration and the proposed truncated one. Comparison of the results for the response displacements and forces shows very good agreement, permitting the acceptance of the pulse duration as the efficient strong motion time interval of the original record, which determines the response and, thus, it can be used for nonlinear structural analyses.

Seismic damage analysis due to near‐fault multipulse ground motion

“…Therein, numerical methods based on nonlinear dynamic response are widely applied due to their advantages in reflecting the nonstationary characteristics of pulselike ground motion and their effectiveness and efficiency. The parameters of pulse-like ground motions, like the peak ground acceleration (PGA), 26 peak ground velocity (PGV), 27 the ratio of the pulse period and structural fundamental period, [28][29][30] response spectrum characteristics, 31,32 frequency-domain feature, 33,34 and duration 35,36 are also widely analyzed and quantitatively evaluated. That the pulse-like ground motion has potential side effects on structural safety is generally recognized.…”

A probabilistic strong floor motion duration model for seismic performance assessment of non‐structural building elements

“…A further insight on the importance of shaking duration was also obtain by reconnaissance reports that documented considerable non-structural damage after seismic events that exhibited moderate intensities and long durations, such as the Nisqually earthquake in 2011, 1 suggesting a direct influence of the earthquake duration in the non-structural damage. Although several recent studies have investigated the influence of strong ground motion duration (SGMD) on the seismic response of structural systems, [21][22][23][24] no specific information could be found by the authors in the public literature on the characterisation of strong floor motion duration (SFMD). This is despite that floor motion duration is a key parameter when selecting historical or generating synthetic floor motions for the seismic response assessment of NSEs or when generating input shake-table test records for the seismic qualification of NSEs.…”

A wavelet-based approach for truncating pulse-like records

“…The scope of this study is to adopt the wavelet-based duration definition proposed by Repapis et al (2020) in order to truncate the acceleration time history and obtain a simpler and shorter signal. The paper shows that this practice can efficiently accelerate the simulation time with minor loss of accuracy.…”