Synthesis of artificial spectrum-compatible seismic accelerograms

Abstract

The Hilbert–Huang transform is used to generate artificial seismic signals compatible with the acceleration spectra of natural seismic records. Artificial spectrum-compatible accelerograms are utilized instead of natural earthquake records for the dynamic response analysis of many critical structures such as hospitals, bridges, and power plants. The realistic estimation of the seismic response of structures involves nonlinear dynamic analysis. Moreover, it requires seismic accelerograms representative of the actual ground acceleration time histories expected at the site of interest. Unfortunately, not many actual records of different seismic intensities are available for many regions. In addition, a large number of seismic accelerograms are required to perform a series of nonlinear dynamic analyses for a reliable statistical investigation of the structural behavior under earthquake excitation. These are the main motivations for generating artificial spectrum-compatible seismic accelerograms and could be useful in earthquake engineering for dynamic analysis and design of buildings. According to the proposed method, a single natural earthquake record is deconstructed into amplitude and frequency components using the Hilbert–Huang transform. The proposed method is illustrated by studying 20 natural seismic records with different characteristics such as different frequency content, amplitude, and duration. Experimental results reveal the efficiency of the proposed method in comparison with well-established and industrial methods in the literature.

Structural damage estimation in mid‐rise reinforced concrete structure based on time–frequency analysis of seismic accelerograms

“…The need for artificially generated earthquakes lies to the need of providing a sufficiently large database for statistical reasons. The generation of artificial accelerograms is achieved via the recently proposed HHT-based method reported by Vrochidou et al [20].…”

Analysis of seismically induced vibrations in turbo machinery foundation for different soil conditions: case study

“…Natural records for an earthquake are very much limited mostly due to the absence of nearby seismic stations in the earthquake site or because of low seismicity variation [9]. An actual seismic record is a non-stationary and nonlinear time series and hence the accuracy of the generated signal to record the natural properties and the characteristics are very much important.…”

“…In Malaysia, due to a lack of recorded representative strong motion data, synthetic ground motions were generated in the frequency domain by carrying out a spectral matching analysis and application of random vibration theory [11]. Vrochidou [9] had compared the generated time history in SeismoArtif software with the values obtained from the Hilbert-Huang transform method.…”

Artificial accelerograms composition based on the CEEMD

“…Several recently reported studies employ the HHT to generate spectrum-compatible seismic accelerograms (Ni et al, 2011, 2013; Vrochidou et al, 2012, 2013; 2014a, 2014b). In methods proposed by Ni et al (2011, 2013), a set of six natural seismic records is essential in order to generate an artificial spectrum-compatible accelerogram.…”

“…Cubic splines can form wide swings if they are left unattended. In order to eliminate end effects in methods proposed by Vrochidou et al (2014a), only the strong motion duration (SMD) of the seismic signal is subjected to the proposed processes. Vrochidou et al (2014a) subject the appropriate frequency components of HHT to data sampling and addition of Gaussian noise.…”