Study on Relationship of Seismic and Pseudo Response Spectrums

2012 ◽  
Vol 238 ◽  
pp. 844-847
Author(s):  
Gong Lian Chen ◽  
Wen Feng Liu ◽  
Gang Li
Keyword(s):  
Design Theory ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Response Spectra ◽  
The Real ◽  
Displacement Response ◽  
Dynamic Relationship ◽  
Performance Based Seismic Design ◽  
The Difference ◽  
Velocity Response Spectrum

153 seismic waves were input into the elastic-dynamic differential equations of single degree of freedom system, the acceleration response spectrum, velocity response spectrum and displacement response spectrum in different site characteristic periods were obtained. According to the pseudo-dynamic relationship between acceleration, velocity and displacement response spectrum, the pseudo response spectra were obtained by the deduction of the 3 real response spectra from the frequency relation. Compared with the value of the real and the pseudo response spectra, the basic characteristics and differences were studied, the correction formulas of the difference between the real response spectrum and the pseudo response spectrum were obtained, the correction formula will contribute to the development of performance based seismic design theory.

scholarly journals A Multi-Objective Ground Motion Selection Approach Matching the Acceleration and Displacement Response Spectra

2018 ◽  
Vol 10 (12) ◽  
pp. 4659 ◽  
Author(s):  
Yabin Chen ◽  
Longjun Xu ◽  
Xingji Zhu ◽  
Hao Liu
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Structural Response ◽  
Response Spectra ◽  
Computationally Efficient ◽  
Ground Motion Selection ◽  
Displacement Response ◽  
Rc Frames ◽  
Selection Approach ◽  
Displacement Response Spectra

For seismic resilience-based design (RBD), a selection of recorded time histories for dynamic structural analysis is usually required. In order to make individual structures and communities regain their target functions as promptly as possible, uncertainty of the structural response estimates is in great need of reduction. The ground motion (GM) selection based on a single target response spectrum, such as acceleration or displacement response spectrum, would bias structural response estimates leading significant uncertainty, even though response spectrum variance is taken into account. In addition, resilience of an individual structure is not governed by its own performance, but depends severely on the performance of other systems in the same community. Thus, evaluation of resilience of a community using records matching target spectrum at whole periods would be reasonable because the fundamental periods of systems in the community may be varied. This paper presents a GM selection approach based on a probabilistic framework to find an optimal set of records to match multiple target spectra, including acceleration and displacement response spectra. Two major steps are included in that framework. Generation of multiple sub-spectra from target displacement response spectrum for selecting sets of GMs was proposed as the first step. Likewise, the process as genetic algorithm (GA), evolvement of individuals previously generated, is the second step, rather than using crossover and mutation techniques. A novel technique improving the match between acceleration response spectra of samples and targets is proposed as the second evolvement step. It is proved computationally efficient for the proposed algorithm by comparing with two developed GM selection algorithms. Finally, the proposed algorithm is applied to select GM records according to seismic codes for analysis of four archetype reinforced concrete (RC) frames aiming to evaluate the influence of GM selection considering two design response spectra on structural responses. The implications of design response spectra especially the displacement response spectrum and GM selection algorithm are summarized.

scholarly journals Unique Method for Generating Design Earthquake Time Histories

2008 ◽  
Author(s):  
R. E. Spears
Keyword(s):  
Response Spectrum ◽  
Low Frequency ◽  
Time History ◽  
Response Spectra ◽  
Cumulative Energy ◽  
Time Histories ◽  
Displacement Response Spectra ◽  
Unique Method ◽  
Design Earthquake ◽  
Velocity Response Spectrum

A method has been developed which takes a seed earthquake time history and modifies it to produce given design response spectra. It is a multi-step process with an initial scaling step and then multiple refinement steps. It is unique in the fact that both the acceleration and displacement response spectra are considered when performing the fit (which primarily improves the low frequency acceleration response spectrum accuracy). Additionally, no matrix inversion is needed. The features include encouraging the code acceleration, velocity, and displacement ratios and attempting to fit the pseudo velocity response spectrum. Also, “smoothing” is done to transition the modified time history to the seed time history at its start and end. This is done in the time history regions below a cumulative energy of 5% and above a cumulative energy of 95%. Finally, the modified acceleration, velocity, and displacement time histories are adjusted to start and end with an amplitude of zero (using Fourier transform techniques for integration).

A Blade Loss Response Spectrum for Flexible Rotor Systems

1985 ◽  
Vol 107 (1) ◽  
pp. 197-204 ◽  
Author(s):  
M. Alam ◽  
H. D. Nelson
Keyword(s):  
Response Spectrum ◽  
Damping Ratio ◽  
Response Spectra ◽  
Flexible Rotor ◽  
Peak Displacement ◽  
Rotor Systems ◽  
Displacement Response ◽  
Modal Damping Ratio ◽  
Whirl Speed ◽  
Blade Loss

A shock spectrum procedure is developed to estimate the peak displacement response of linear flexible rotor-bearing systems subjected to a step change in unbalance (i.e., a blade loss). A progressive and a retrograde response spectrum are established. These blade loss response spectra are expressed in a unique non-dimensional form and are functions of the modal damping ratio and the ratio of rotor spin speed to modal damped whirl speed. Modal decomposition using complex modes is utilized to make use of the unique feature of the spectra for the calculation of the peak blade loss displacement response of the rotor system. The procedure is applied to three example systems using several modal superposition strategies. The results of each are compared to true peak displacements obtained by a separate transient response program.

Research Progress of Structural Seismic Design Thought

2012 ◽  
Vol 457-458 ◽  
pp. 1420-1423
Author(s):  
Ting Yue Hao
Keyword(s):  
Seismic Design ◽  
Design Theory ◽  
Design Method ◽  
Response Spectrum ◽  
Theoretical Research ◽  
Research Progress ◽  
Analysis Theory ◽  
Performance Based Seismic Design ◽  
Seismic Design Method ◽  
Design Ideas

Research progress of structural seismic design theory is analyzed and collated in this paper, including static analysis theory, theory of response spectrum, dynamic theory. The three theoretical research and design methods are analyzed and described in the paper one by one. At last, modern seismic design method which is called performance-based seismic design theory is compared and analyzed with the traditional anti-seismic design theory. Its advanced characteristics and advantages are obtained, which will be the core and development of seismic design ideas.

Generation of Spectrum-Compatible Earthquake Motion Using Wavelet Transform

2002 ◽  
Author(s):  
Arata Masuda ◽  
Akira Sone
Keyword(s):  
Wavelet Transform ◽  
Response Spectrum ◽  
Impulse Response Function ◽  
Maximum Amplitude ◽  
Response Spectra ◽  
Frequency Characteristics ◽  
Time Frequency ◽  
Earthquake Motion ◽  
Velocity Response Spectrum ◽  
Velocity Impulse

In this paper, a new method for generating artificial earthquake motions is proposed, in which one can explicitly design the time-frequency characteristics of the earthquake as well as its response spectra. First, it is shown that the velocity response spectrum at a specific period can be interpreted as the maximum amplitude of the wavelet transform in which the velocity impulse response function of a single-degree-of-freedom system is used as the analyzing wavelet. Using this relationship, a spectrum-compatible artificial earthquake motion with the desirable time-frequency characteristics is generated in the wavelet domain by an iterative correction-projection scheme. Some illustrative examples are investigated to demonstrate the capability and the practicability of the proposed scheme.

scholarly journals Design Response Spectra Based on Earthquake Hazard Maps and Specific Soil Properties at Indonesian Ports According to SNI 1726 2019

2021 ◽  
Vol 17 (1) ◽  
pp. 41-54
Author(s):  
Christino Boyke Surya Permana
Keyword(s):  
Site Response ◽  
Response Spectrum ◽  
Earthquake Hazard ◽  
Response Spectra ◽  
Site Response Analysis ◽  
Response Analysis ◽  
Spectral Acceleration ◽  
Hazard Maps ◽  
The Difference ◽  
S Period

Indonesia has a new seismic code, namely SNI 1726 2019 (SNI 2019). It is developed based on the 2017 Indonesian Earthquake Source, Hazard Maps, and ASCE 7-16. This paper is intended to explain the procedure for calculating response spectrum according to SNI 1726 2019, at ten ports located in Indonesia. The results are then verified with the software RSA2019.  Furthermore, it will be compared to SNI 1726 2012 (SNI 2012) to see the difference in spectral acceleration value (Sa). The result presents that the ports located in Sorong and Banggai have the highest Sa, whereas the port in Banjarmasin has the smallest value. Port in Surabaya and Tuban have nearly the same Sa due to their close location, while Banyuwangi has a Sa value slightly above them. The ports in Padang, Lampung, and Penajam must use a specific site response analysis to determine the design response spectra, which is not discussed in this paper. The comparison with SNI 2012 shows that the response spectra of SNI 2019 have a higher Sa than SNI 2012. However, in some areas such as Tuban and Sorong, the Sa of SNI 2012 at 0.1 to 0.6 s period are larger than SNI 2019.  

Response Spectrum Method for Submerged Structures

2008 ◽  
Author(s):  
B. L. Ly ◽  
Y. An
Keyword(s):  
Response Spectrum ◽  
Mass Matrix ◽  
Response Spectra ◽  
Degree Of Freedom ◽  
Virtual Mass ◽  
Practical Applications ◽  
Floor Response Spectra ◽  
Mass Matrices ◽  
The Difference ◽  
Work Done

A submerged structure has virtual mass matrix in the inertial term and wet mass matrix in the driving term in the equation of motion, whereas a dry structure has the same mass matrix in these two terms. If a finite element code for dry structures is used to analyze a submerged structure, the results should be adjusted. Result for a Single Degree of Freedom (SDOF) system is scaled by the ratio of wet mass to virtual mass. Results for a Multiple Degree of Freedom (MDOF) system are adjusted by scaling the Floor Response Spectra (FRS) at each modal frequency by a ratio of modal work done in that mode by the wet mass matrix to that by the virtual mass matrix. The adjustment factor can be estimated as a product of a ratio of participation factors and a ratio of modal masses. Both the participation factors and the modal masses are computed by using the wet mass matrix, and then by using the virtual mass matrix, respectively. This method provides an alternative way to assess the margin in the design based on the current FRS method that does not distinguish the difference between the two mass matrices. More studies should be carried out to implement this method in specific practical applications.

ANALYTICAL INDICATOR. ANALYSIS OF THE REAL STATE OF DYNAMICS OF MORTALITY OF THE POPULATION OF RUSSIA FROM MALIGNANT TUMORS AND CHANGES IN ITS STRUCTURE

2019 ◽  
Vol 65 (2) ◽  
pp. 205-219 ◽  
Author(s):  
V. Merabishvili
Keyword(s):  
Malignant Tumors ◽  
Specific Weight ◽  
Mortality Rates ◽  
Retirement Age ◽  
Medium Term ◽  
Age Composition ◽  
The Real ◽  
Indicator Analysis ◽  
The Difference ◽  
Real State

The mortality rate is one of the most important criteria for assessing the health of the population. However, it is important to use analytical indicators correctly, especially when evaluating time series. The value of the “gross” mortality is closely linked with a specific weight of persons of elderly and senile ages. All international publications (WHO, IARC, territorial cancer registers) assess the dynamics of morbidity and mortality only by standardized indicators that eliminate the difference in the age composition of the compared population groups. In Russia, from 1960 to 2017, the share of people of retirement age has increased more than 2 times. The structure of mortality from malignant tumors has changed dramatically. The paper presents the dynamics of gross and standardized mortality rates from malignant tumors in Russia and in all administrative territories. Shows the real success of the Oncology service. The medium-term interval forecast until 2025 has been calculated.

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