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ZHANG Xin-jun YING Lei-dong 《浙江大学学报(A卷英文版)》2007,8(5):693-698
To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable’s cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge, its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable’s cross-sectional area should be deter-mined by the principle of equivalent axial stiffness. 相似文献
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以某双塔单索面人行钢斜拉桥为对象,采用Midas Civil建立全桥空间杆系有限元模型,进行恒载、活载和承载能力极限状态作用下结构受力性能分析,同时开展该桥的动力特性分析。研究表明:对于该异形斜拉桥,活载引起的主梁和主塔弯矩效应较恒载作用下的结果更加显著;承载能力极限状态作用下,该桥主梁、主塔、斜拉索等主要承重构件的最大应力均小于材料容许应力,满足规范要求;动力特性分析结果表明主梁面内刚度和主塔面外刚度较小,此外遮阳棚的局部振动在高阶振型中所占比例较大,在地震作用下可能发生破坏;该桥的一阶竖向自振频率为1.92 Hz,不满足现行规范要求,建议采取有效的减振措施来控制人致振动响应。 相似文献
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研究目的：通过非线性动力有限元分析,模拟多塔斜拉桥在多点激励下的地震响应以及揭爪其在强震下的倒塌破坏模式。创新要点：解决了多塔斜拉桥的非线性动力数值模拟技术,并首次模拟了多塔斜拉桥在强震下的破坏模式。研究方法：首先采用隐式的Newmark-β法求解多点地震激励下的非线性动力方程（图3）,随后采用显式的中心差分格式对强震作用下桥梁的倒塌破坏过程进行数值仿真（图4）。重要结论：1．单主梁模犁的数值结果可以很好地反映地震模拟振动台试验的地震响应结果;2．在加速度峰值为4．0m／s2的E1。Centro波时,多塔斜拉桥模型只出现了中塔支座的破坏;3．在加速度峰值为4．0m／s2的江心波时,多塔斜拉桥模型先后出现了支序破坏、拉索与塔的连接破坏以及中塔上塔柱段的单元失效。 相似文献
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程怡 《福建工程学院学报》2018,(4):320-325
以某跨径为110 m的独塔异形斜拉桥为工程背景,通过非线性有限元分析对斜拉桥在强震作用下的地震响应特性及减震措施进行了研究,得出如下结论:相比Lander-amboy波,卓越周期与桥梁固有周期较为接近的Cerro Prieto波能够引起结构较大的地震响应。行波效应能够显著增大工程背景斜拉桥的地震响应,且随着视波速的增大,桥梁的加速度响应明显增大。阻尼系数25 000 kN·s/m为工程背景斜拉桥的最优粘滞阻尼器设计参数,且在塔梁连接处安装该参数粘滞阻尼器后,斜拉桥减震效果显著,尤其能明显减小结构的位移响应。 相似文献
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彭卫 《金华职业技术学院学报》2005,5(3):1-4,8
斜拉桥的拉索构件柔度大、阻尼小、质量轻，在风的激励下会产生涡激振动、尾流驰振和风雨激振。研究方法有风洞实验、理论分析和数值模拟。对近年来的研究成果包括各种研究方法的现状、风振控制措施以及存在问题进行了归纳。 相似文献
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为检验在役大跨径悬索桥结构的动力性能,对主跨128 m地锚式悬索桥进行动力试验.测试其自振频率、振型和阻尼比;激振试验中,测试桥跨结构在汽车以不同速度通过桥跨和在桥上特定位置跳车时桥跨结构的动应变、动位移、振幅以及加速度等动力响应,计算得出冲击系数.并将实测结果与有限元结果进行对比分析.结果表明,该悬索桥具有较好的竖向刚度、横向刚度;汽车在桥上运行时对桥跨结构有一定的冲击作用但并不明显,有障碍行车舒适度较差. 相似文献
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This paper proposes a new numerical simulation method for analyzing the parametric vibration of stay cables based on the theory of nonlinear dynamic response of structures under the asynchronous support excitation. The effects of important parameters related to parametric vibration of cables, i.e., characteristics of structure, excitation frequency, excitation amplitude, damping effect of the air and the viscous damping coefficient of the cables, were investigated by using the proposed method for the cables with significant length difference as examples. The analysis results show that nonlinear finite element method is a powerful technique in analyzing the parametric vibration of cables, the behavior of parametric vibration of the two cables with different Irvine parameters has similar properties, the amplitudes of parametric vibration of cables are related to the frequency and amplitude of harmonic support excitations and the effect of distributed viscous damping on parametric vibration of the cables is very small. 相似文献
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Alternate path(AP) method is the most widely used method for the progressive collapse analysis,and its application in frame structures has been well proved.However,the application of AP method for other structures,especially for cable-stayed structures,should be further developed.The four analytical procedures,i.e.,linear static,nonlinear static,linear dynamic,and nonlinear dynamic were firstly improved by taking into account the initial state.Then a cable-stayed structure was studied using the four improved methods.Furthermore,the losses of both one cable and two cables were discussed.The results show that for static and dynamic analyses of the cable-stayed bridges,there is large difference between the results obtained from simulations starting with either a deformed or a nondeformed configuration at the time of cable loss.The static results are conservative in the vicinity of the ruptured cable,but the dynamic effect of the cable loss in the area farther away from the loss-cable cannot be considered.Moreover,the dynamic amplification factor of 2.0 is found to be a good estimate for static analysis procedures,since linear static and linear dynamic procedures yield approximately the same maximum vertical deflection.The results of the comprehensive evaluation of the cable failure show that the tread of the progressive failure of the cable-stayed bridges decreases when the location of the failed cables is closer to the pylon. 相似文献
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Nonlinear vibration can cause serious problems in long span cable-stayed bridges.When the internal resonance threshold is reached between the excitation frequency and natural frequency,large amplitudes occur in the cable.Based on the current situation of lacking corresponding constraint criteria,a model was presented for analyzing the dynamic reliability of coupling oscillation between the cable and tower in a cable-stayed bridge.First of all,in the case of cable sag,the d'Alembert principle is applied to studying the nonlinear dynamic behavior of the structure,and resonance failure interval of parametric oscillation is calculated accordingly.Then the dynamic reliability model is set up using the JC method.An application of this model has been developed for the preliminary design of one cable-stayed bridge located on Hai River in Tianjin,and time histories analysis as well as reliability indexes have been obtained.When frequency ratio between the cable and tower is approaching 1∶2,the reliability index is 0.98,indicating high failure probability.And this is consistent with theoretical derivation and experimental results in reference.This model,which is capable of computing the reliability index of resonance failure,provides theoretical basis for the establishment of corresponding rule. 相似文献
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研究目的：创新要点：为多塔斜拉桥在一致激励和非一致激励下地震响应的研究提供地震模拟振动台全桥试验方法,并有助于加强多塔斜拉桥抗震性能和抗震设计的认识。1．建立了地震模拟振动台多台阵试验方法,并首次将其应用于多塔斜拉桥全桥比例缩尺模型的地震响应分析之中;2．通过地震模拟振动台试验,揭示了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性并提出了多塔斜拉桥在强震下的破坏模式。研究方法：1．基于动力相似理论,设计与制作了多塔斜拉桥的全桥比例缩尺模型（图2）;2．利用地震模拟振动台多台阵试验,根据在不同地震波作用下和考虑行波效应后多塔斜拉桥模型的主梁和主塔响应,分析了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性（图5～图8）;3．根据在地震波不同强度作用下多塔斜拉桥模型的主梁和主塔响虚,分析了多塔斜拉桥在强震下的破坏模式和地震响应（图9）。重要结论：1．江心波作用下该多塔斜拉桥的地震响应大于其他三种地震波;2．多塔斜拉桥在抗震设计时需要考虑行波效应的影响;3．在El-Centro波的加速度峰值高达4．0m／s^2时,多塔斜拉桥模型出现了支座破坏。 相似文献
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Hao WANG Tian-you TAO Huai-yu CHENG Ai-qun LI 《浙江大学学报(A卷英文版)》2014,(10):798-812
研究目的：为超大跨度斜拉桥抗风设计与抖振控制提供参考。研究方法：基于ANSYS建立了苏通大桥三维有限元模型,并在MATLAB平台模拟了苏通大桥三维脉动风场。考虑主梁断面气动自激力,进行了苏通大桥抖振时域分析。根据苏通大桥动力特性和抖振时域分析结果,重点分析了多重调谐质量阻尼器（MTMD）用于抖振控制的参数敏感性。考虑MTMD的控制效果、建造费用、施工难度及鲁棒性等因素建立了关于MTMD设计参数的目标函数,并基于一阶优化算法进行目标函数最优解的非线性搜索,据此获得了MTMD在约束条件下的最优设计参数。重要结论：1.苏通大桥侧向抖振位移主要由第一阶侧弯振型控制,竖向抖振位移主要由第一阶竖弯振型控制;2.MTMD的控制效果对设计参数的变化十分敏感,其中质量比和频带宽敏感性更强;3.MTMD的最优设计参数可以通过一阶优化算法获得,并可通过零阶优化算法对优化结果进行验证;4.采用优化后的MTMD设计参数,苏通大桥的抖振响应可以得到明显抑制,且侧向抖振控制效果更加明显。 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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为检验在役双曲拱桥的承载能力与动力特性,对某净跨为36 m空腹式双曲拱桥进行了静载试验、动载试验及空间有限元分析。测试结构的静态应变、动态应变、挠度、自振频率、振型及加速度等结构反应,计算得出冲击系数。将实测结果与有限元结果进行对比分析,结果表明:应变校验系数为0.5~0.9,结构具有较好承载力。实测的各阶频率及相应振型与有限元计算结果比较吻合,桥梁整体竖向刚度较好。 相似文献
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颜桂云 《福建工程学院学报》2012,(1):12-16
为检验在役混凝土拱桥的承载能力与动力特性,对某净跨为134.7m的拱桥进行荷载试验。测试结构静态的应变、桥面挠度、拱肋挠度、吊索变形、吊索索力等结构静力反应。同时,测试了结构自振频率、动挠度及加速度等结构动力反应,根据动挠度计算得出冲击系数。将实测值与理论值进行对比分析。结果表明,应变校验系数在0.7～1.0之间,实测的挠度、吊索索力、频率及冲击系数均小于理论值,说明桥梁具有较好承载力和整体竖向刚度较好。试验方法与分析结果为今后评估与鉴定同类型桥梁提供理论依据和技术参考。 相似文献
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从结构构造和力学特点两个方面进行对比分析,得出斜拉桥随着跨径的增加,拉索与主梁的夹角逐渐变小,竖向有效分力也随着变小,因此,斜拉桥的跨越能力会受到限制,推导了最佳的高跨比范围;悬索桥吊杆与加劲梁是垂直或斜向交叉,不会随着跨径加大而受影响,悬索桥比斜拉桥的跨越能力更大. 相似文献
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为了建立实测动响应和桥梁健康状况的实质性联系,提出用双层模型修正方法修正叠合梁斜拉桥理论计算模型.以实测固有频率为第1层修正目标,采用人工调节方法,在可靠范围内变化桥面板质量、网格划分密度、混凝土模量及边跨压重等参数修正模型的动力特性;然后以GPS实测动响应为第2层修正目标,通过逐步减小结构各向刚度EI模拟桥梁整体刚度损伤,采用有限元迭代的方法修正模型的挠度值.以南浦大桥为例,对其进行有限元建模,并利用所提出的方法进行模型修正.分析结果表明,经过第1层模型修正,频率误差的标准偏差小于7%,比初始误差有明显改善;经过第2层模型修正,桥梁跨中挠度误差小于10%,桥梁结构各向刚度EI下降约20%.研究结果表明理论计算结果与实测结果相吻合. 相似文献
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鉴于矮塔斜拉桥受力性能的特殊性,引入增量动力分析（IDA）和拉丁超立方体抽样（LHS）评估该结构在地震激励下发生损伤的风险概率。首先采用LHS考虑桥梁构件材料的随机性,与事先选取的地震波相结合形成桥梁-地震动样本集合;其次在确定桥梁有限元模型主要构件损伤指标的基础上采用基于蒙特卡罗（MC）抽样的IDA进行地震易损性分析和地震风险概率评估。为验证方法的正确性和有效性,对一预应力混凝土独塔双索面矮塔斜拉桥结构模型进行地震风险概率评估,结果表明:该方法既充分考虑了材料和地震输入双重随机性又避免了繁琐的积分过程,同时也提高了工程计算的效率及精度。 相似文献
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双边轮式斜拉桥悬索检测机器人设计与分析(英文) 总被引：1，自引：0，他引：1
为了检测斜拉桥圆柱形悬索内部钢丝情况,设计了一种新型的双边轮式悬索爬升机器人,简述了其机械结构及运动方式,建立了爬升模型,分析了其机构的静态特性,并以直径为139 mm的悬索为例给出了相关设计参数.为使机构在电路系统故障时能安全回收,提出了一种基于反电动势理论的安全节能回收方法,应用曲柄滑块驱动气缸设计了气体阻尼机构,以消耗机构下降时因重力作用产生的多余动能,并建立了机构数学模型来仿真下降速度.试验结果表明,所设计的机器人能携带3.5 kg重物沿直径为65～205 mm的悬索平稳运行,满足了悬索检测的实用要求. 相似文献