【作者】 丁德豪；

【导师】 单德山；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2012， 硕士

【摘要】 通过对有限元模型参数的识别与修正,不断减小实测值与有限元模型计算值之间差距,并最终建立能够反映结构现有实际状态的有限元模型,其本质是有限元模型优化问题。基于有限元理论,在一定的假设和抽象的基础上,即可建立任何桥梁结构的有限元模型,该模型不一定能真实反映桥梁结构的实际工作状态,即与桥梁原型之间存在误差,进而使得其有限元模型计算值无法作为桥梁响应的代表结果,为确保计算结果能真实表达实际工程中的桥梁结构,应对其有限元模型进行修正。有限元模型修正在桥梁健康监测系统设计与损伤评估、桥梁管养系统设计等方面均有广泛的应用,有限元模型修正的研究具有工程实用价值。主要工作内容包括：1、回顾有限元模型修正技术的发展历程,总结有限元模型修正方法,分析各种方法的优缺点、存在的问题；2、引入子结构与径向基神经网络相结合的方法进行有限元模型修正,将“反问题”转化为“正问题”进行求解；3、结合有限元模型修正问题的特点,对径向基神经网络的输入输出参数进行分析,并确定径向基神经网络修正有限元模型的技术路线；4、对预应力混凝土简支梁进行有限元模型修正,验证本文所提方法的可行性；5、利用随机子空间法对单塔斜拉桥实测动力数据进行分析,获得结构固有频率和模态,并依据此数据修正单塔斜拉桥有限元模型。修正后有限元模型计算值与实测值之间误差较原有设计模型有很大程度改进。更多还原

【Abstract】 Finite element model updating is the process of decreasing the gap between the measured value and the calculated value of the finite element model through the identifying and updating of design parameters, and establish the finite element model to reflect the actual state of the existing structure, essentially within the optimization problem.The finite element model updating has wide applications in the design and damage assessment of bridge health monitoring system, the bridge custody system design, thus, the finite element model updating study has good practical value.The main work includes:1. Review the course of development of the finite element model updating, and summarize the finite element model updating methods, to analyze the advantages and disadvantages and problems of each method;2. The introduction of combining sub-structure and radial basis function neural network method as finite element model updating tool of this thesis, the "inverse problem" transformed into "normal problem" is solved;3. Consider the characteristics of the finite element model updating problems, analyse the input and output parameters of radial basis function neural network, and determine the technology roadmap using the radial basis function neural network to update the finite element model;4. Update the prestressed concrete simply supported beam finite element model, and verify the feasibility of the proposed method;5. Using stochastic subspace method to analyze the measured dynamic data of the single pylon cable-stayed bridge, access to the structural natural frequencies and mode, it is used to update the single pylon cable-stayed bridge. The gap between the calculation results of updated finite element model and measured value is much more decrease than the original design finite element model.更多还原