基于梁格法的刚构拱桥静动力力学性能分析

发布时间：2018-04-15 13:47

本文选题：刚构拱组合桥 + 梁格法　；参考：《北京交通大学》2017年硕士论文

【摘要】：随着我国高速铁路梁桥的快速发展和行车速度不断提升,越来越多的大跨度桥梁的被应用于桥梁建设之中,这些都对数值仿真模拟计算桥梁结构特性提出了必然的要求。现有的桥梁有限元结构计算中主要依托单一梁体模型和精细化的桥梁实体模型进行计算,但单一梁体模型不能反应细部结构变化,模型较为"粗糙"实体模型随着桥梁跨度的增加,节点和单元数量的增多会产生巨大的计算量,不便于进行研究计算。因此需要针对桥梁结构进行简化模型计算。剪力柔性梁格法是针对混凝土桥梁较为常用的桥梁结构简化方法之一,但其简化过程是基于结构各项刚度进行的静力简化,结构动力特性是否与原结构一致还有待验证。因此,针对以上问题,本文着力于梁拱组合桥静动力性能分析及其研究,主要进行了以下几个方面的工作。(1)系统梳理了梁拱组合桥的国内外的工程案例以及发展现状,对近年来国内外拱桥有限元分析成果、稳定理论等相关内容进行了总结概述。介绍和梳理了本文研究所要使用的梁格计算理论和多体动力学相关建模理论,为计算和研究奠定理论基础。(2)基于高速铁路常用桥梁结构的刚构拱组合桥进行有限元计算,分别建立了单一梁体模型和梁格模型,对两种模型的静动力特性进行了验证,通过静力特性对比验证了模型计算的可靠性,通过模态分析对比两类模型结果差异,通过模态的数值和形状对比验证梁格模型可用于动力计算。(3)将有限元软件MIDAS/CIVIL中计算的桥梁结构数据结果,导入有限元软件ANSYS中并与多体动力学软件UM结合起来,计算了基于梁格法建模的车桥耦合振动响应,并根据规范对车辆的走行性进行了验证。验证了车辆在150km/h～250km/h行驶速度下,车辆竖向加速度最大值为1.118m/s2,横向加速度最大值为0.862m/s2,轮对的减载率最大值为0.372,脱轨系数最大值为0.218,轮重减载率小于第二限度0.6。车辆脱轨系数小于第二限度1.0,列车能安全行驶通过桥梁。桥梁中跨跨中的竖向挠度最大值为6.096mm,横向挠度值为5.092mm,均满足预应力混凝土桥梁竖向挠度要求和桥梁横向振幅要求限值。桥梁、车辆响应结果均满足走行性安全标准,车辆能够安全行驶通过基于梁格简化的桥梁结构。(4)以基于梁格法的模型基础参数入手,研究结构在变参数下的梁格结构的动力特性变化。对刚度、拱肋刚度变化下的结构各阶模态的数值和形状变化进行了分析和验证,发现桥梁结构中拱肋刚度变化对结构自振特性影响相对较大,变参数下的结构自振特性只发生了数值变化,未出现振型形状变化。(5)对比在不同时速下,桥梁结构参数对其车桥耦合响应结果的影响,在考虑车辆行驶速度的影响下,针对梁格法桥梁的动力特性进行分析。发现梁格变参数对桥梁动力性能的影响主要通过参数变化对结构自身刚度的影响来实现,并在研究基于梁格法简化的桥梁动力性能的过程中,从桥梁的各阶模态分析入手,针对结构的模态进行参数优化。本文通过数据对比研究为梁格法简化的桥梁结构车桥耦合动力性能分析提供参数优化依据。
[Abstract]:With the rapid development of China's high-speed railway bridge and train speed increasing, more and more long span bridges are used in bridge construction, the numerical simulation of the simulation of the necessary calculation of structure characteristics of bridge is proposed. The structure of the existing bridge finite element calculation is mainly based on single beam model and refined Bridge model to calculate, but single beam model can not reflect the detailed structure changes, the model is "rough" solid model with the increase of bridge span, increase in the number of nodes and units will have a huge amount of computation and is not easy to study. Therefore we need to calculate the bridge structure simplified model for calculating shear flexible beam. Is one of the methods based on the simplified method of bridge structure of concrete bridge is more commonly used, but its simplified process is simplified the structure static stiffness based on structure Whether the dynamic characteristics consistent with the original structure remains to be verified. Therefore, in view of the above problems, this paper focuses on the composite arch bridge static and dynamic performance analysis and research, mainly in the following aspects. (1) describe the domestic and foreign engineering case beam arch bridge and the development of the status quo, in China in recent years the outer arch bridge finite element analysis results, stability theory and other related content are summarized. This paper introduces and clarifies the grillage Institute to use the calculation theory and multi-body dynamics modeling theory, which lays the theoretical foundation for the calculation and research. (2) commonly used in high-speed railway bridge of rigid frame arch composite bridge finite element based on the calculation, the single beam model and grillage model are established, the static and dynamic characteristics of the two models is validated, the reliability model of calculation is verified by comparing the static characteristics, through modal Comparative analysis of two kinds of model results, by comparing the numerical and modal shape verification grillage model can be used for dynamic calculation. (3) the calculation of the finite element software MIDAS/CIVIL bridge structure data into the finite element software ANSYS and multi-body dynamics software UM combined calculation of vehicle bridge coupling vibration of the grillage model based on response, and according to the specification of the vehicle running safety was verified. Verify the vehicle in the 150km/h ~ 250km/h speed, vehicle vertical acceleration maximum lateral acceleration is 1.118m/s2, the maximum value is 0.862m/s2, the wheel load reduction rate of the maximum value is 0.372, the derailment coefficient maximum value is 0.218, wheel load reduction the rate of less than second 0.6. limit vehicle derailment coefficient is less than second limit of 1, the train can be safe driving through the bridge. The bridge across the maximum vertical deflection is 6.096mm, lateral deflection value is 5.092mm That satisfies the lateral amplitude of vertical deflection of prestressed concrete bridge and Bridge limit. The bridge vehicle response results satisfy walking safety standard, the vehicle can be safely driven by bridge girder based on simplified. (4) to start the foundation of grillage method based on model parameters, change dynamic characteristic of structure change the grillage structure parameters. On the stiffness, analyze and validate the numerical and structural changes of shape change arch rib rigidity under the modal, found arch rib rigidity of bridge structure change influence on the natural vibration characteristics of relatively large, the structural parameter under the vibration characteristics of only numerical change does not appear, modal shape change. (5) comparison at different speeds, the impact response of the bridge structure parameters of the vehicle bridge coupling, in consideration of the influences of the vehicle speed, the dynamic characteristics of beam bridge Were analyzed. To realize the influence of lattice beam variable parameters on the dynamic performance of the bridge is mainly through the parameter change on the structure's stiffness is found, and in the study of dynamic performance of bridge based on grillage method simplified the process, from the analysis of the various modes of the bridge, the structural modal parameters were optimized. The analysis of bridge structure bridge coupled dynamic performance by comparing the data for parameter optimization of grillage method simplified to provide basis.

【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

【参考文献】