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Your search keyword '"Kanai-Tajimi"' showing total 6 results
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6 results on '"Kanai-Tajimi"'

1. Geração de uma excitação sísmica através do espectro de Kanai-Tajimi

Author

Daniela Dalla Chiesa and Letícia Fleck Fadel Miguel

Subjects
Excitação sísmica, Kanai-Tajimi, MATLAB, Electronic computers. Computer science, QA75.5-76.95
Abstract

O presente artigo apresenta os resultados da implementação de uma rotina computacional, no programa MATLAB, para a geração de uma excitação sísmica e análise da resposta dinâmica de um edifício, com n graus de liberdade, sujeito a esse tipo de carregamento. Define-se a excitação sísmica como um processo estocástico estacionário unidimensional, passando por um processo de ruído branco Gaussiano através do filtro de Kanai-Tajimi, cuja função densidade espectral de potência permite a geração da aceleração do solo no domínio da frequência. A aceleração do solo é, então, passada para o domínio do tempo gerando um acelerograma sísmico artificial. De posse do acelerograma resolve-se, com a aplicação do método de Newmark, a equação de movimento dinâmico estrutural e encontram-se os deslocamentos, velocidades e acelerações referentes a cada andar do edifício. Por fim, uma análise dos valores máximos, em módulo, dos deslocamentos, acelerações e dos deslocamentos relativos entre os andares é ilustrada. Os resultados encontrados estão condizentes com a literatura confirmando, assim, a eficiência da rotina implementada.

Published
2017
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2. On the performance of double rolling isolation systems.

Author

Calhoun, S.J., Tehrani, M.H., and Harvey, P.S.

Subjects
*WHITE noise, *STOCHASTIC analysis, *NONLINEAR equations, *EQUATIONS of motion, *TELECOMMUNICATION equipment, *DETERMINISTIC algorithms, *LINEAR equations, *MAP design
Abstract

Abstract Harvey and Gavin [1] previously proposed a double rolling isolation system (RIS) that possesses greater displacement capacity than that of its constituent subsystems alone. This study aims to quantify the performance gained by using the dual-layer system. The system's nonlinear equations of motion, adhering to the constraint of rolling without slipping, are derived for arbitrary rolling profiles. Linear equations are recovered when a circular rolling profile is assumed. The stochastic response of the double RIS under stationary white noise excitation is evaluated for relevant system parameters, namely mass ratio and tuning frequency. Both broadband and filtered (Kanai-Tajimi) white noise excitation are considered. The response variances of the double RIS are normalized by a baseline single RIS for a comparative study, from which parameter design maps are drawn. A deterministic analysis was also conducted to further evaluate the double RIS in the case of nonstationary excitation. The telecommunications equipment qualification waveform, VERTEQII, was used for these numerical simulations. Peak transient responses are compared to the single RIS responses, and optimal design regions are determined. General design guidelines based on the stochastic and deterministic analyses are given. Highlights • A double rolling isolation system for seismic protection is studied. • The system has greater displacement capacity than that of its constituent subsystems alone. • A nonlinear model adhering to the kinematic constraint of rolling without slipping is derived. • The system's performance is evaluated through stochastic and deterministic analyses. [ABSTRACT FROM AUTHOR]

Published
2019
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3. Dynamic Behavior of an Isolated Bridge Pier under Earthquake Effects for Different Soil layers and Support Conditions

Author

Sarıtaş, Fevzi and Hasgür, Zeki

Subjects
Piers, Stochastic systems, Time domain analysis, Earthquake acceleration, Peak responses, Bridge piers, Thermoelectricity, İnşaat Mühendisliği, Kanai-Tajimi, Finite element techniques, Peak responses,rubber,Kanai-Tajimi,nonstationary,stochastic, Nonstationary, Stochastic, Power spectrum, Probability distributions, Dynamic response, Earthquakes, Frequency domain analysis, Time and frequency domains, Soils, Rubber, Peak response, Probabilistic distribution
Abstract

An isolated bridge pier having rubber bearings is modeled by finite element technique and dynamic responses under effects of earthquake accelerations are obtained by linear solution methods in time and frequency domain; the results are evaluated by probabilistic distributions. For this purpose, stationary accelerations characterized by Kanai-Tajimi power spectrum are simulated for different soil types and twenty nonstationary records in each soil group are obtained by modulating the amplitudes in harmony with Erzincan NS 1992 component. The pier responses and deck displacements are obtained in time domain for different support and soil conditions by using simulated horizontal and vertical accelerations. Furthermore, variances of the responses are obtained in frequency domain by assuming stationary stochastic behavior and by using power density and cross-power spectra of the applied simultaneous motions. The results are evaluated by those of the time domain solutions and peak responses and variations of peak response factors are determined. For dynamic peak responses, the response quantities corresponding to exceedance probabilities of 2%, 10% and 50% (median) are predicted depending upon soil types by use Rayleigh distribution model.

Published
2015

4. Earthquake Effects for Different Soil layers and Support Conditions

Author

Saritas, F and Hasgur, Z

Subjects
Peak responses, rubber, Kanai-Tajimi, nonstationary, stochastic
Abstract

An isolated bridge pier having elastomeric bearings is modeled by finite element technique and dynamic responses under the effect of earthquake accelerations which are obtained by linear solution methods in time and frequency domain and the results are evaluated by probabilistic distributions. For this purpose, stationary accelerations characterized by Kanai-Tajimi power spectrum are simulated for different soil types and twenty nonstationary records in each soil group are obtained by modulating the amplitudes in harmony with 1992 Erzincan earthquake NS component. The pier responses and deck displacements are obtained in time domain for different support and soil conditions by using simulated horizontal and vertical accelerations. Furthermore, variances of the responses are obtained in frequency domain by assuming stationary stochastic behavior and by using power density and cross-power spectra of the applied simultaneous motions. The results are evaluated by those of the time domain solutions and peak responses and variations of peak response factors are determined. For dynamic peak responses, the response quantities corresponding to exceedance probabilities of 2%, 10% and 50% (median) are predicted depending upon soil types by use of Rayleigh distribution model.

Published
2014

5. Dynamic behavior of bridge pier with elastomeric bearings under earthquake effects for different soil layers and support conditions

Author

Sarıtaş, Fevzi and Hasgür, Zeki

Subjects
Stochastic systems, Earthquake acceleration, Time domain analysis, Peak responses, Bridge piers, Bridge bearings, Thermoelectricity, Kanai-Tajimi, Finite element techniques, Nonstationary, Stochastic, Power spectrum, Probability distributions, Dynamic response, Earthquakes, Frequency domain analysis, Soils, Time and frequency domains, Rubber, Peak response, Probabilistic distribution
Abstract

An isolated bridge pier having elastomeric bearings is modeled by finite element technique and dynamic responses under the effect of earthquake accelerations which are obtained by linear solution methods in time and frequency domain and the results are evaluated by probabilistic distributions. For this purpose, stationary accelerations characterized by Kanai-Tajimi power spectrum are simulated for different soil types and twenty nonstationary records in each soil group are obtained by modulating the amplitudes in harmony with 1992 Erzincan earthquake NS component. The pier responses and deck displacements are obtained in time domain for different support and soil conditions by using simulated horizontal and vertical accelerations. Furthermore, variances of the responses are obtained in frequency domain by assuming stationary stochastic behavior and by using power density and cross-power spectra of the applied simultaneous motions. The results are evaluated by those of the time domain solutions and peak responses and variations of peak response factors are determined. For dynamic peak responses, the response quantities corresponding to exceedance probabilities of 2%, 10% and 50% (median) are predicted depending upon soil types by use of Rayleigh distribution model.

Published
2014

6. Discussion of ‘A new approach of selecting real input ground motions for seismic design: The most unfavourable real seismic design ground motions’ by C-H Zhai and L-L Xie

Author

Moustafa, Abbas and Moustafa, Abbas

Abstract

This discussion consists of two parts. The first part raises a few comments and questions on the method presented in the above paper. The second part proposes a measure for identifying resonant accelerograms in a set of earthquake records without the need for pre-processing of the records or inclusion of the structure dynamic analysis., Earthquake Engineering & Structural Dynamics, 38(9), pp. 1143-1149; 2009

Published
2009

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