A Stochastic Approach to Nonlinear Seismic Design Spectra

18th International Conference on Nuclear Engineering: Volume 5 ◽

10.1115/icone18-30146 ◽

2010 ◽

Author(s):

Malek Brahimi

Keyword(s):

Yield Strength ◽

Ground Motion ◽

Nonlinear Response ◽

Moving Average ◽

Response Spectra ◽

Stochastic Approach ◽

Earthquake Ground Motion ◽

Autoregressive Moving Average ◽

Design Spectra ◽

Nonlinear Design

The purpose of this study is to examine the effects of yield strength ratios and damping values on the nonlinear response of Single Degree of Freedom Systems (S.D.F.S) subjected to earthquake ground motion. A stochastic approach to constructing design response spectra and period dependent strength reduction factors for current existing nonlinear design spectra is then proposed. Non-stationary stochastic models are adopted to characterize earthquake ground motion. Twenty simulated earthquakes accelerograms are generated for each of eight historical events using Autoregressive Moving Average (ARMA) techniques. The average of nonlinear response spectra for a given Structural period from a sample of twenty records for each event are calculated to obtain the response spectra. These response spectra are used to examine the effects of structural strength factors such as the yield strength ratio and damping value, and the effects of nonlinear stiffness models including the elastoplasic model, a stiffness degrading model and a stiffness softening model.

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Time Series Modeling of Earthquake Ground Motions Using ARMA-GARCH Models

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.470.240 ◽

2013 ◽

Vol 470 ◽

pp. 240-243 ◽

Cited By ~ 1

Author(s):

Jeng Hsiang Lin

Keyword(s):

Ground Motion ◽

Moving Average ◽

Ground Motions ◽

Structural Response ◽

Earthquake Ground Motion ◽

Response Analysis ◽

Practical Implementation ◽

Autoregressive Moving Average ◽

Arma Models ◽

Earthquake Models

Engineers are well aware that, due to the stochastic nature of earthquake ground motion, the information obtained from structural response analysis using scant records is quite unreliable. Thus, providing earthquake models for specific sites or areas of research and practical implementation is essential. This paper presents a procedure for the modeling strong earthquake ground motion based on autoregressive moving average (ARMA) models. The Generalized autoregressive conditional heteroskedasticity (GARCH) model is used to simulate the time-varying characteristics of earthquakes.

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The Earthquake Ground Motion and Response Spectra Design for Sleman, Yogyakarta, Indonesia with Probabilistic Seismic Hazard Analysis and Spectral Matching in Time Domain

American Journal of Civil Engineering ◽

10.11648/j.ajce.20160406.15 ◽

2016 ◽

Vol 4 (6) ◽

pp. 298

Author(s):

Lalu Makrup

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Time Domain ◽

Hazard Analysis ◽

Response Spectra ◽

Probabilistic Seismic Hazard Analysis ◽

Seismic Hazard Analysis ◽

Earthquake Ground Motion ◽

Probabilistic Seismic Hazard ◽

Spectral Matching

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Evaluation of Earthquake Response Spectra Directionality Using Stochastic Simulations

Bulletin of the Seismological Society of America ◽

10.1785/0120210101 ◽

2021 ◽

Author(s):

Alan Poulos ◽

Eduardo Miranda ◽

Jack W. Baker

Keyword(s):

Stochastic Process ◽

Ground Motion ◽

Ground Motions ◽

Gaussian White Noise ◽

Response Spectra ◽

Orientation Dependence ◽

Stochastic Simulations ◽

Earthquake Ground Motion ◽

Significant Duration ◽

Simulated Ground Motions

ABSTRACT For earthquake-resistant design purposes, ground-motion intensity is usually characterized using response spectra. The amplitude of response spectral ordinates of horizontal components varies significantly with changes in orientation. This change in intensity with orientation is commonly known as ground-motion directionality. Although this directionality has been attributed to several factors, such as topographic irregularities, near-fault effects, and local geologic heterogeneities, the mechanism behind this phenomenon is still not well understood. This work studies the directionality characteristics of earthquake ground-motion intensity using synthetic ground motions and compares their directionality to that of recorded ground motions. The two principal components of horizontal acceleration are sampled independently using a stochastic model based on finite-duration time-modulated filtered Gaussian white-noise processes. By using the same stochastic process to sample both horizontal components of motion, the variance of horizontal ground acceleration has negligible orientation dependence. However, these simulations’ response spectral ordinates present directionality levels comparable to those found in real ground motions. It is shown that the directionality of the simulated ground motions changes for each realization of the stochastic process and is a consequence of the duration being finite. Simulated ground motions also present similar directionality trends to recorded earthquake ground motions, such as the increase of average directionality with increasing period of vibration and decrease with increasing significant duration. These results suggest that most of the orientation dependence of horizontal response spectra is primarily explained by the finite significant duration of earthquake ground motion causing inherent randomness in response spectra, rather than by some physical mechanism causing polarization of shaking.

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