TY - JOUR
ID - 4254
TI - On the Evolutionary Characteristics of the Acceleration Records Generated From Linear Time-Variant Systems
JO - Scientia Iranica
JA - SCI
LA - en
SN - 1026-3098
AU - Waezi, Zakariya
AU - R. Rofooei, Fayaz
AD - Civil Engineering
Department, Sharif University of Technology, Tehran, Iran
AD - Department of Civil Engineering, Sharif University of Technology, Tehran, Iran
Y1 - 2017
PY - 2017
VL - 24
IS - 6
SP - 2817
EP - 2831
KW - Non-stationary records
KW - Ground motion simulation
KW - Linear time variant
KW - Zero crossing
KW - Positive minimum and Negative maximum
KW - Lower-level crossings
DO - 10.24200/sci.2017.4254
N2 - This paper discusses the time-varying characteristics of the output signals resulted from linear time variant (LTV) systems using level crossing properties. These systems which are used for generating synthetic records based on a target record contain two identification processes: 1) amplitude modulating function, 2) time-varying impulse response function (IRF) parameters. For efficient tracking of the IRF parameters, the zero-crossing and positive minima/negative maxima cumulative curves are usually utilized as the measures of the instantaneous spectral power. Using spectral moments, analytic relations for zero-crossing and positive minima/negative maxima cumulative count are developed with respect to the IRF’s evolutionary power spectrum. In order to efficiently investigate the low-frequency components of the output records, the zero-crossing rate of the velocity and the displacement records are tracked and rigorous analytic equations for their descriptions are developed. Some of the issues concerning application of the developed equations are explored using two LVT models, and the limitations of the proposed procedures are explained. Through introduction of new compatibility measures, the necessity of implementing Monte Carlo simulations would no longer be needed and it would be possible to generate the synthetic acceleration records with desirable evolutionary characteristics with much less computation time.
UR - http://scientiairanica.sharif.edu/article_4254.html
L1 - http://scientiairanica.sharif.edu/article_4254_92a5577457dd70f1b45552ed573b2995.pdf
ER -