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During cantilever cast in construction of high-pier and large-span continuous rigid frame bridges, structural stability in the longest cantilevered stage is very important. Based on a practical design case of a large-span continuous rigid frame bridge in Wuhan, the longest span stability coefficient is calculated with linear-buckling and nonlinear-buckling methods, respectively. The influences of both geometrical nonlinearity and the dual nonlinearity of material and geometry are considered. Numerical results indicate that the nonlinear solution is necessary to stability analysis because linear buckling loads axe much higher than those of nonlinear buckling. Thus, the edge fiber yield criterion is more convenient and faster than ultimate loading criterion when estimating nonlinear stability of structure, and can be used easily in the initial engineering design. 相似文献
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光纤光栅传感技术在桥梁结构健康监测中的应用 总被引:4,自引:0,他引:4
概述了光纤Bragg光栅传感器的基本原理及特点。介绍了目前光纤Bragg光栅传感器在国外、国内桥梁结构健康监测中的研究及应用情况。指出了光纤Bragg光栅传感器在桥梁结构健康监测领域的应用前景。 相似文献
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传感器优化布置在桥梁结构模态参数测试中的应用 总被引:1,自引:1,他引:0
介绍了一种桥梁结构模态参数测试中传感器优化布置的局部次优方法,也就是逐步消减法,该法基于识别误差最小原则,力求使得感兴趣的模态向量尽可能的线性无关。首先根据矩阵理论,通过QR分解使得矩阵列向量组具有较大范数,然后以MAC矩阵的最大非对角元为目标函数,根据传感器的可选位置对MAC矩阵的贡献大小,从剩余传感器的可选位置中去掉对目标函数贡献最小的可选位置,直到传感器数目达到最理想的数目。这种方法简单而且计算效率高,最后通过一个工程实例,验证了该法的可行性和有效性,具有广阔的工程应用前景。 相似文献
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In order to assess the effects of tuned mass dampers (TMDs) on wind actions, an aeroelastic model with a scale of 1:60 was constructed. Tests were performed in an atmospheric boundary layer wind tunnel to investigate the buffeting response of the pylon with a TMD fixed by a wire rope instead of a spring. The model was tested under different levels of damping. The experimental and numerical results showed that with the TMD in the optimal condition, the buffeting response was reduced by 47%. 相似文献
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斜拉桥异形截面索塔锚固区足尺模型试验与应力分析 总被引:1,自引:0,他引:1
斜拉桥索塔锚固区是桥梁结构的关键受力部位,特别是对于异形截面形式的桥塔来说,单纯的力学分析很难反映结构的实际工作状态与应力分布状况。为此,针对马岭河特大桥非对称六边形索塔锚固区进行足尺节段模型试验,对试验过程中节段模型裂缝的产生、发展及应力等进行观测和分析,并对索塔锚固区节段进行空间有限元分析。结果表明,试验和理论分析结果符合程度较好,索塔锚固区连接部位外侧以及折线形长边内侧转角2个区域是开裂敏感区,其抗裂安全系数为1.3,破坏安全系数为1.6。 相似文献
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随着我国高速公路建设的迅猛发展,毛勒及仿毛勒伸缩装置得到广泛应用,与此同时,桥梁伸缩装置处跳车成为一种较普遍的病害.文中对桥梁伸缩装置处跳车现象产生的原因进行了分析,提出了防治措施和维修方法,以期从根本上解决桥梁伸缩装置处跳车问题. 相似文献
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Based on strain signals,a new time-domain methodology for detecting the beam local damage has been developed.The pseudo strain energy density (PSED) is defined and used to build two major damage indexes,the average pseudo strain energy density (APSED) and the average pseudo strain energy density rate (APSEDR).Probability and mathematical statistics are utilized to derive a standardized damage index.Furthermore,by applying the analytic relation between the strain energy release rate and the stress intensity factor,an analytic solution of crack depth is derived.For the dynamic strain signals,the wavelet packet transform is used to pre-process measured data.Finally,a numerical simulation indicates that this method can effectively identify the damage location and its absolute severity. 相似文献
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杭州湾跨海大桥北航道桥斜拉索减振研究 总被引:2,自引:1,他引:1
运用福斯(Foss)迭代法求解设置黏性剪切阻尼器(VSD)减振拉索的振动方程,得到复特征值和对数衰减率。以对数衰减率大于等于0.03为目标函数,对杭州湾跨海大桥北航道桥斜拉索减振用VSD进行优化设计,并对安装VSD的减振效果进行分析。结果表明:减振拉索的每阶模态均有对应的VSD最优插板面积,高阶模态的最优插板面积小于低阶模态,高阶模态的对数衰减率受插板面积的影响比低阶模态大;在不考虑其他因素条件下插板面积大于150cm2时便可有效抑制斜拉索的各种风致振动;高阶模态的最大对数衰减率所对应的温度高于低模态最大对数衰减率所对应的温度,低温时低阶模态的对数衰减率大于高阶模态的对数衰减率,温度较高时高阶模态的对数衰减率大于低阶模态的对数衰减率。杭州湾跨海大桥北航道桥斜拉索安装VSD后,对数衰减率从0.015~0.0196提高到0.03~0.11,有效地减小了斜拉索的各种风致振动,达到了减振效果及设计目标。 相似文献