Errors of structural seismic responses caused by frequency filtering based on seismic wave synthesis

Earthquake is a kind of natural disaster which is difficult to predict and the damage degree is very great, occurrence of the strong motion often leads to the tremendous life and property loss. Bridge is very important lifeline engineering and it is very necessary to conduct the comprehensive and systemic investigation on the bridge aseismic. In this paper, the FEM model of a long-span cable-bridge was established; the dynamic characteristic and nonlinear seismic responses under uniform and non-uniform excitations of it were systematic studied. The results show that: 1) the basic cycle of it is about 8.881s. Its first mode of vibration is longitudinal floating mode, which is favorable to the earthquake-response of structures. 2) Its former 40 rank frequency are located between 0.1~2Hz which is avail to the condition of traffic condition.3) the geometric nonlinearity has much influence on the response of this kind of bridge.4) the seismic responses are sensitive to the frequency spectra of the input earthquake wave. 5) The traveling wave excitations are unfavorable to the design of tower and the main girder when considering the three orthogonal seismic wave input. In order to get correct results, artificial seismic wave of the bridge address is necessary to the time-history analysis.

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Nonlinear Earthquake-Response Analysis of Wuhan Junshan Yangtze River under Uniform and Non-Uniform Excitations

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.1220 ◽

2011 ◽

Vol 105-107 ◽

pp. 1220-1224

Author(s):

Kai Yan Xu ◽

De Min Wei ◽

Can Liu

Keyword(s):

Seismic Wave ◽

Yangtze River ◽

Time History ◽

Earthquake Response ◽

Response Analysis ◽

Seismic Responses ◽

Traffic Condition ◽

Frequency Spectra ◽

History Analysis ◽

Earthquake Response Analysis

Wuhan Junshan Yangtze River Bridge is an important traffic hinge on Jing-Zhu freeway, it is very necessary to conduct the comprehensive and systemic investigation on the bridge aseismic. In this paper, the FEM model of it was established; the dynamic characteristic and nonlinear seismic responses under uniform and non-uniform excitations of it were systematic studied. The results show that: 1) the basic cycle of Wuhan Junshan Yangtze River Bridge is about 8.881s. Its first mode of vibration is longitudinal floating mode, which is favorable to the earthquake- response of structures. 2) Its former 40 rank frequency are located between 0.1~2Hz which is avail to the condition of traffic condition.3) the geometric nonlinearity has much influence on the response of this kind of bridge.4) the seismic responses are sensitive to the frequency spectra of the input earthquake wave. 5) The traveling wave excitations are unfavorable to the design of tower and the main girder when considering the three orthogonal seismic wave input. In order to get correct results, artificial seismic wave of the bridge address is necessary to the time-history analysis.

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Comparison on Seismic Responses of Different Caisson-Soil Interaction Models of a Single Tower Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.2123 ◽

2013 ◽

Vol 353-356 ◽

pp. 2123-2126

Author(s):

Tian Bo Peng ◽

Xin Xie ◽

Lei Han

Keyword(s):

Finite Element ◽

Linear Model ◽

Seismic Wave ◽

Nonlinear Models ◽

Seismic Responses ◽

Interaction Models ◽

Nonlinear Properties ◽

Finite Element Software ◽

Tower Structure

In order to study the effect of different models on caisson-soil interaction, a linear model and two nonlinear models are established by finite element software SAP2000. It is found that with the increase of amplitude of seismic wave, the effect of nonlinear properties of caisson-soil interaction is increasingly large. The linear model, however, is not suitable any more under such condition, while the nonlinear models can simulate caisson-soil interaction reasonably.

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Study on the Seismic Response of High-Speed Rotational Disk-Shaft System

Volume 8: Seismic Engineering ◽

10.1115/pvp2012-78029 ◽

2012 ◽

Author(s):

Tomohiro Ito ◽

Masayoshi Hatta ◽

Atsuhiko Shintani ◽

Chihiro Nakagawa

Keyword(s):

Seismic Response ◽

Seismic Wave ◽

High Speed ◽

Equations Of Motion ◽

Rotating Disk ◽

Seismic Responses ◽

Shaft System ◽

High Speed Rotation ◽

Gyroscopic Effects ◽

Response Behaviors

Recently, huge earthquakes occurred in the world, such as Great East Japan Earthquake in Japan or huge earthquake in New Zealand in 2011. In Niigata-ken Chuetsuoki earthquake in 2007, turbine blade collisions with the casing were found. Therefore, it is very important to clarify the seismic response behaviors of the high-speed rotational shaft like turbine shafts, because high-speed rotation will cause characteristic dynamic effects, such as gyro moment. In this study, seismic responses of a disk-shaft system are evaluated analytically. The disk-shaft system is treated as an elastic shaft with a rigid disk. In this analysis, gyroscopic effects of a rotating disk are also considered. Equations of motion are derived for the translational and rotational motions when the system is subjected to both horizontal and vertical seismic excitations. Response behaviors of a rotating disk-shaft system are evaluated for sinusoidal excitations and seismic wave excitations. In the sinusoidal excitations, excitation frequencies and rotational speed are varied, and in the seismic wave excitations, seismic responses are evaluated for the waves with various predominant frequencies.

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