scholarly journals Efficient Method for Selecting Ground Motions with a Mean Response Spectrum Matching a Target Spectrum

2011 ◽  
Vol 15 (5) ◽  
pp. 1-10 ◽  
Author(s):  
Sang-Whan Han ◽  
Seung-Wook Seok
Keyword(s):  
Efficient Method ◽  
Response Spectrum ◽  
Ground Motions ◽  
Target Spectrum ◽  
Spectrum Matching

A Semi-Automated Procedure for Selecting and Scaling Recorded Earthquake Motions for Dynamic Analysis

2008 ◽  
Vol 24 (4) ◽  
pp. 911-932 ◽  
Author(s):  
Albert Kottke ◽  
Ellen M. Rathje
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Ground Motions ◽  
Acceleration Response ◽  
Analysis Process ◽  
Target Spectrum ◽  
Acceleration Response Spectrum ◽  
Individual Scale ◽  
The Individual ◽  
Selection Of

Suites of earthquake ground motions play an important role in the seismic design and analysis process. A semi-automated procedure is described that selects and scales ground motions to fit a target acceleration response spectrum, while at the same time the procedure controls the variability within the ground motion suite. The basic methodology selects motions based on matching the target spectral shape, and then fits the amplitude and standard deviation of the target by adjusting the individual scale factors for the motions. The selection of motions from a larger catalog of motions is performed through either a rigorous method that tries each possible suite of motions or an iterative approach that considers a smaller set of potential suites in an effort to find suites that provide an acceptable fit to the target spectrum. Guidelines are provided regarding the application of the developed procedures, and example applications are described.

A Metric to Screen Acceptable Velocity and Displacement Time Histories of Modified Ground Motions

2017 ◽  
Vol 33 (4) ◽  
pp. 1495-1512
Author(s):  
Clinton P. Carlson ◽  
Dimitrios Zekkos
Keyword(s):  
Goodness Of Fit ◽  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Visual Assessment ◽  
Acceleration Response ◽  
Earthquake Scenarios ◽  
Target Spectrum ◽  
Time Histories ◽  
Acceleration Response Spectrum

Ground motion modification is extensively used in practice to modify a seed acceleration time history in intensity and frequency content until its acceleration response spectrum matches a target spectrum. However, the decision to accept or reject a modified motion commonly relies on a subjective process where the time histories of the modified motion are visually compared to those of the seed motion. Various metrics were used to quantify the similarity between the modified time histories and their scaled counterparts for hundreds of modified ground motions from three different earthquake scenarios. Of the metrics considered, the inverse modified RMSE metric for time histories ( imRMSE t) was found most appropriate as it resulted in the least amount of dispersion in the goodness-of-fit values with respect to spectral mismatch. The imRMSE t was then found to be correlated to qualitative rankings assigned to the modified time histories through a visual assessment. The correlation between the quantitative imRMSE t values and qualitative rankings is used to establish threshold values to screen modified velocity and displacement time histories that are likely acceptable or likely unacceptable.

Seismic response analysis of steel–concrete hybrid wind turbine tower

2021 ◽  
pp. 107754632110075
Author(s):  
Junling Chen ◽  
Jinwei Li ◽  
Dawei Wang ◽  
Youquan Feng
Keyword(s):  
Wind Turbine ◽  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Seismic Action ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Wind Turbine Tower ◽  
Ground Types ◽  
Nonlinear Time History

The steel–concrete hybrid wind turbine tower is characterized by the concrete tubular segment at the lower part and the traditional steel tubular segment at the upper part. Because of the great change of mass and stiffness along the height of the tower at the connection of steel segment and concrete segment, its dynamic responses under seismic ground motions are significantly different from those of the traditional steel tubular wind turbine tower. Two detailed finite element models of a full steel tubular tower and a steel–concrete hybrid tower for 2.0 MW wind turbine built in the same wind farm are, respectively, developed by using the finite element software ABAQUS. The response spectrum method is applied to analyze the seismic action effects of these two towers under three different ground types. Three groups of ground motions corresponding to three ground types are used to analyze the dynamic response of the steel–concrete hybrid tower by the nonlinear time history method. The numerical results show that the seismic action effect by the response spectrum method is lower than those by the nonlinear time history method. And then it can be concluded that the response spectrum method is not suitable for calculating the seismic action effects of the steel–concrete hybrid tower directly and the time history analyses should be a necessary supplement for its seismic design. The first three modes have obvious contributions on the dynamic response of the steel–concrete hybrid tower.

scholarly journals Simulation of response spectrum-compatible ground motions using wavelet-based multi-resolution analysis

2021 ◽  
pp. 002029402110130
Author(s):  
Guan Chen ◽  
Zhiren Zhu ◽  
Jun Hu
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Ground Motions ◽  
Power Spectra ◽  
Simulation Method ◽  
Eurocode 8 ◽  
Effective Response ◽  
Multi Resolution Analysis ◽  
Resolution Analysis ◽  
Simulated Ground Motions

This study proposed a simple and effective response spectrum-compatible ground motions simulation method to mitigate the scarcity of ground motions on seismic hazard analysis base on wavelet-based multi-resolution analysis. The feasibility of the proposed method is illustrated with two recorded ground motions in El Mayor-Cucapah earthquake. The results show that the proposed method enriches the ground motions exponentially. The simulated ground motions agree well with the attenuation characteristics of seismic ground motion without modulating process. Moreover, the pseudo-acceleration response spectrum error between the recorded ground motion and the average of the simulated ground motions is 5.2%, which fulfills the requirement prescribed in Eurocode 8 for artificially simulated ground motions. Besides, the cumulative power spectra between the simulated and recorded ground motions agree well on both high- and low-frequency regions. Therefore, the proposed method offers a feasible alternative in enriching response spectrum-compatible ground motions, especially on the regions with insufficient ground motions.

Response spectral matching of horizontal ground motion components to an orientation-independent spectrum (RotDnn)

2020 ◽  
pp. 875529302097098
Author(s):  
Luis A Montejo
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Response Spectra ◽  
Major Axis ◽  
Component Level ◽  
Nonlinear Characteristics ◽  
Target Spectrum ◽  
Horizontal Ground Motion ◽  
Median Spectrum

This article presents a methodology to spectrally match two horizontal ground motion components to an orientation-independent target spectrum (RotDnn). The algorithm is based on the continuous wavelet transform decomposition and iterative manipulation of the two horizontal components of a seed record. The numerical examples presented follow current ASCE/SEI 7 specifications and therefore maximum-direction spectra (RotD100) are used as target for the match. However, the proposed methodology can be used to match other RotDnn spectra, like the median spectrum (RotD50). It is shown that with the proposed methodology the resulting RotDnn from the modified horizontal components closely match the smooth target RotDnn spectrum, while the response spectrum for each horizontal component continue to exhibit a realistic jagged behavior. The response spectra variability at the component level within suites of spectrally matched motions was found to be of the same order than the variability measured in suites composed of amplitude scaled records. Moreover, the spectrally matched records generated preserved most of the characteristics of the seed records, including the nonlinear characteristics of the time history traces and the period-dependent major axis orientations.

Inelastic Response of a Spectrum-Compatible Artificial Accelerogram

1989 ◽  
Vol 5 (3) ◽  
pp. 477-493 ◽  
Author(s):  
Michael E. Barenberg
Keyword(s):  
Response Spectrum ◽  
Ground Motions ◽  
Normalization Procedure ◽  
Target Response ◽  
Single Degree Of Freedom ◽  
Inelastic Response ◽  
Strong Ground Motions ◽  
Single Degree ◽  
Initial Frequency ◽  
Strong Ground

The validity of evaluating the inelastic response of a structure subjected to an artificial accelerogram in lieu of a suite of eight recorded ground motions is determined by analyzing the inelastic response of single-degree-of-freedom oscillators over a range of frequencies from 1.0 to 10.0 Hz. A normalization procedure to minimize the dispersion in the ductility response of the oscillators subjected to the recorded ground motions is investigated. The artificial accelerogram is derived by superimposing closely spaced sine waves in order to match a target response spectrum. The results show that the artificial accelerogram is expected to produce the same amount of damage as the average of the recorded strong ground motions for structures with an initial frequency of less than 5.0 Hz and close to the average for the entire suite of ground motions for structures with frequencies greater then 5.0 Hz.

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