Simulation of fling step pulse of near-fault ground motion by using wavelet smoothening and improved bell-shaped function

Ezzodin, Amir; Amiri, Gholamreza Ghodrati; Dehkordi, Morteza Raissi

doi:10.1016/j.soildyn.2020.106462

Cited by 8 publications

(6 citation statements)

References 25 publications

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“…Several studies (e.g., [32][33][34][35][36][37][38]) have simulated the nearfault velocity pulse. In the present study, however, the fingstep pulse suggested by Ezzodin et al [38] and the extracted pulse by using wavelet transform were utilized to analyze the efect of the near-fault pulse on the damage detection procedure. It should be noted that the damage caused by each record was taken into account at the starting point of the following ground motion.…”

Section: Finite Element Modeling and Earthquake Simulationmentioning

confidence: 99%

“…Table 3 indicates the details of the utilized records. Te acceleration component of the considered earthquake records, the pulse extracted by Ezzodin et al [38], and the pulse extracted by using the wavelet transform are demonstrated in Figure 6. In addition, Figure 7 shows all 9 records with white noises.…”

Section: Finite Element Modeling and Earthquake Simulationmentioning

confidence: 99%

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A Novel Damage Detection Method of Reinforced Concrete Frames Using Signal Processing and Extracted Near-Fault Fling-Step Pulses

Ezzodin

Amiri

Naderpour

et al. 2022

Shock and Vibration

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A new model-free output-only signal processing-based damage detection procedure was carried out in this paper. First of all, a finite element model as the representative of reinforced concrete (RC) frames was constructed and subjected to a specific loading protocol in OpenSees. The protocol consisted of 9 consequent different near-fault fling-step pulse-type earthquake records with low-amplitude white noises among them to simulate the collapse procedure. The analysis process was complemented in three levels: (a) the Fourier transform was utilized to extract the vibration frequency, (b) the time instants of damage occurrence were detected by using the discrete wavelet transform, and (c) accurate damage detection was made by using the extracted pulse components of the records as loading protocol for earthquake simulation and the discrete wavelet transform. The results revealed that the proposed combinatorial method could efficiently diagnose the damage in the RC frames. Also, applying a pulse component instead of an original record increases the accuracy of damage detection by 70%.

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Section: Finite Element Modeling and Earthquake Simulationmentioning

confidence: 99%

Section: Finite Element Modeling and Earthquake Simulationmentioning

confidence: 99%

A Novel Damage Detection Method of Reinforced Concrete Frames Using Signal Processing and Extracted Near-Fault Fling-Step Pulses

Ezzodin

Amiri

Naderpour

et al. 2022

Shock and Vibration

Self Cite

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“…Other than the identification of pulse-like features, there are ever increasing demands for the parameterization of velocity pulses, for example, either in the stochastic simulation of near-fault motions, [37][38][39][40][41][42][43][44][45][46] or in the study regarding the influence of velocity pulses on engineered structures. [10][11][12][47][48][49][50][51][52][53] To parameterize the velocity pulse, there is a need of removing the high-frequency content that may hamper an automated extraction of the pulses of interest.…”

Section: Introductionmentioning

confidence: 99%

“…However, this is not the case for analytical models with one-sided pulses, which would always lead to permanent displacements and are generally adopted to simulate pulses possibly resulting from the fling-step effects. 9,16,40,42,96 Moreover, a key advantage of using the proposed approach is that multiple pulses can be easily extracted and quantified. That is, with N c varying from 0.5 to 3, a large quantity of pulses with multiple consecutive half-cycles can be identi-fied; in addition, variation of the phase shift 𝜑 from -𝜋 to 𝜋 greatly improves the fitting quality of V(𝑡; θ) to ṽ(𝑡) in the time and spectral domains.…”

mentioning

confidence: 99%

Automated parameterization of velocity pulses in near‐fault ground motions

Chang,

Wu,

Goda

2023

Earthq Engng Struct Dyn

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Proper parameterization of near‐fault ground motions is of critical importance in earthquake engineering, and this process is traditionally performed by directly fitting an analytical pulse model to the original motion. Yet such a process is usually limited by the trial‐and‐error procedure, which is strongly dependent on the initial guesses and may converge to local rather than global minimums. In this study, we propose a progressive (step‐by‐step) iterative approach that can achieve a fully automated parameterization of the velocity pulse contained in near‐fault motions. Assuming that a velocity pulse can be characterized by a pulse model with four key parameters, the approach is conducted by iteratively matching the pulse model to the smoothed ground motion, and the parameterized pulse is analytically derived by best fitting to the smoothed motion not only in the time domain but also in the spectral domain. Specifically, the velocity time history of interest is initially smoothed by a moving average filter so that the low‐frequency content can be filtered out of the original motion, from which the pulse amplitude as well as its epoch is accordingly determined. The coherent velocity pulse is then progressively extracted by performing the nonlinear least‐square‐fitting of the pulse model to the filtered low‐frequency content, during which the remaining parameters, that is, the pulse period, the number of cycles and the phase of the pulse, are estimated successively. Finally, the above procedure is applied repeatedly to the original ground motion by changing an empirical factor controlling the extent of smoothing of the motion so that convergence to local minimums that frequently occurs in the trial‐and‐error procedure could be largely avoided, and best match of the spectrum of the extracted pulse to that of the original motion can be acquired. Fitting quality of the velocity pulses is examined by comparing with existing methods. Prospective applications of the proposed procedure include the stochastic simulations of near‐fault ground motions and parametric investigations of the influence of velocity pulses on various engineered structures.

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“…In view of the shortcomings of wavelet technology in identifying pulse-like ground motions, many improved methods to define velocity pulse by using pulse energy are proposed [22]. e results show that the ground motion with the main velocity pulse with relative energy greater than 0.3 can be classified as pulse-like ground motion [23].…”

Section: Introductionmentioning

confidence: 99%

Quantitative Identification of Pulse‐Like Ground Motions Based on Hilbert–Huang Transform

Liu

2021

Shock and Vibration

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Aiming to address the problem of pulse-like ground motions being difficult to identify, this paper refines the Baker’s wavelet-based pulse-like ground motions identification method, followed by a new pulse-like ground motion identification method based on Hilbert–Huang Transform (HHT) being proposed. In this method, HHT is used to decompose ground motions instead of wavelet. HHT can overcome the dependence of wavelet analysis on the selection of mother wave, and thus more complex velocity pulses can be identified. In order to compare the effects of two pulse-like ground motion identification methods, HHT-based method and wavelet-based method, respectively, are used to identify ground motions in Pacific Earthquake Engineering Research Center (PEER). After identifying the 3066 groups of ground motions selected from PEER, it is found that the HHT-based method can identify 229 pulse-like ground motions, and the wavelet-based method can identify 150 pulse-like ground motions. More complex shapes of near-fault velocity pulses can be extracted by the HHT-based method. By analyzing the seismic response, fault distance, and cumulative squared velocity (CSV) of these pulse-like ground motions, it is found that the pulse-like ground motions identified by the HHT-based method have strong near-fault characteristics. If a high recognition quality can be guaranteed, the proposed HHT-based method can identify many kinds of near-fault velocity pulses and thus provide more pulse-like ground motions for seismic researches.

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Simulation of fling step pulse of near-fault ground motion by using wavelet smoothening and improved bell-shaped function

Cited by 8 publications

References 25 publications

A Novel Damage Detection Method of Reinforced Concrete Frames Using Signal Processing and Extracted Near-Fault Fling-Step Pulses

A Novel Damage Detection Method of Reinforced Concrete Frames Using Signal Processing and Extracted Near-Fault Fling-Step Pulses

Automated parameterization of velocity pulses in near‐fault ground motions

Quantitative Identification of Pulse‐Like Ground Motions Based on Hilbert–Huang Transform

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