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INTRODUCTIONIthasbeenrecognizedthatlong spanbridg es ,cable supportedbridgesinparticular,aresubjecttothedynamicwindaction .Theaerody namicstability (flutter)ofsuspensionbridgesduringerectionisasubjectofmajorconcernforresearchersandengineers .Althoughtheperi… 相似文献
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INTRODUCTIONWiththedevelopmentofcomputertechnologyandnumericalmethods,numericalsimulationtechniqueshavebecomeneweffectiveapproachesforthepredictionofwindvelocitiesaroundbuild ingsandwind inducedpressuresonthebuildingenvelope (Murakamietal.,1 988;Baskaranet… 相似文献
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In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined
by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic
forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable
when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule.
It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear
factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection.
Project supported by National Natural Science Foundation of China(No. 598954410), and China Postdoctoral Science Foundation
(No. 2002031245) 相似文献
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This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of
stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in
the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed
through numerical, calculation. It is noted that parametrically excited oscillation of a stay cable with certain, sag, inclination
angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the
natural frequency of a cable approaches to about half of the, first model frequency of the bridge deck system. A new vibration
control system installed on the cable anchorage is proposed as a possible damping system to suppress, the cable parametric
oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due
to the vibration of the deck and/or towers will be considerably reduced.
Project supported by National Natural Science Foundation of China (No. 59978044) 相似文献
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INTRODUCTION Due to the increasing number of building story braced by transferring member during development of high or superhigh rise buildings, and the many de-mands and restrictions on floor height and space in architecture, it is necessary to use steel reinforced concrete (SRC) materials in transferring structure. SRC has high bearing capacity, good stiffness and relatively less section dimension, and ductility, dura-bility and aseismic behavior better than that of rein-forced concre… 相似文献
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Too many sensors and data information in structural health monitoring system raise the problem of how to realize multi-sensor information fusion. An experiment on a three-story frame structure was conducted to obtain vibration test data in 36 damage cases. A coupling neural network (NN) based on multi-sensor information fusion is proposed to achieve identification of damage occurrence, damage localization and damage quantification, respectively. First, wavelet packet transform (WPT) is used to extract features of vibration test data from structure with different damage extent. Then, data fusion is conducted by assembling feature vectors of different type sensors. Finally, three sets of coupling NN are constructed to implement decision fusion and damage identification. The results of experimental study proved the validity and feasibility of the proposed methodology. 相似文献
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INTRODUCTIONCable stayedbridgesarewidelyappliedinmodernbridgestructuralsystem .Thelargestspanofcable stayedbridgeiscloseto 1 0 0 0mwhenmanynewmaterialsandtechnologiesareapplied.Thestaycablesareimportantbridgestructurecomponentsmostpronetoexhibithighamplitu… 相似文献
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MR阻尼器的力学模型都是以电压为已知量,来求阻尼器的出力.而在结构控制中,通常是由控制算法先求出需要的控制力,由此控制力反推出相应的电压,从而控制阻尼器的输入电压来使其产生需要的力.由于MR阻尼器是一种强非线性半主动控制装置,由阻尼器的阻尼力反推其输入电压是一个复杂而困难的问题.本文利用神经网络强大的学习、非线性拟合等... 相似文献