【作者】 赵海涛；

【导师】 张文首；

【作者基本信息】 大连理工大学 ， 工程力学， 2021， 硕士

【摘要】 由于铁路站房作为重要交通枢纽,人流量大,运行时间长,一旦因为结构疲劳或者维修不及时而造成结构失效,甚至结构坍塌,不仅会造成相当严重的经济损失,还会造成不良的社会影响。为了确保铁路站房在计划运营时间内能稳定运行,不至于因某些结构损伤造成不必要的损失,对铁路站房进行健康监测,并对其进行损伤评估和寿命预测,就十分必要了。本文以襄阳东津站为研究对象,对其进行了以下研究:(1)由于有限元模型与真实结构之间存在较大的误差,为使有限元模型能够反映结构真实的静动力特性,就需要对有限元模型进行模型修正,而模型修正需要一些结构的真实静动力信息来构造目标函数,在结构信息中频率是较为常用的,但实际上结构频率并不能直接获取,只能通过对结构信号做相应处理才能得到。因此本文首先采用随机子空间法对东津站模型进行模态参数识别,研究是否能通过对东津站有限元模型的加速度信号转换得到模型的频率信息,以验证算法的有效性。(2)采用模型修正技术对襄阳东津站进行模型修正,运用ANSYS当中的一阶优化方法,以结构的真实频率和有限元模型的测试频率之间的相对误差构造目标函数,对有限元模型进行模型修正,使得经过修正的有限元模型与真实结构之间频率误差减小,进而使有限元模型更全面地反映真实结构的静动态响应。(3)利用ANSYS对襄阳东津站的网架结构杆单元及整体结构柱单元分别进行敏感性分析确定出热点单元。对襄阳东津站进行疲劳损伤评估与寿命预测,将修正后的有限元模型作为基础模型,对其施加风荷载、地震作用,提取结构热点单元的应力时程数据,运用雨流计数法进行处理,并利用Goodman曲线和Gerber曲线对雨流法得到的应力幅值和应力均值进行处理得到等效应力幅值,分别根据Miner累积损伤理论和修正的Miner累积损伤理论得到一定时间段内的各种载荷循环作用后热点单元的损伤程度,进而推算出结构热点单元的剩余寿命。更多还原

【Abstract】 As an important transportation hub,railway station buildings have large passenger flow and long operation time.Once structural failure or even structural collapse is caused by structural fatigue or overdue maintenance,it will not only cause serious economic losses,but also cause bad social influence.In order to ensure the stable operation of railway station buildings during the planned operation time and avoid unnecessary loss caused by some structural damage,it is necessary to carry out health monitoring,damage assessment and life prediction on railway station buildings.This thesis takes Xiangyang Dongjin Station as the research object and conducts the following research on it:(1)Due to the larger error between the finite element model and real structure,in order to make the finite element model can reflect the real static and dynamic characteristics of the structure,it is necessary to modify the finite element model,and it is in need of some real static and dynamic information of the structure to construct the objective function,the frequency is more commonly used in the structural information,but in fact the structural frequency can not directly access,it can only be obtained by corresponding processing of structural signals.So this thesis identifies the modal parameters of the Dongjin Station model by the stochastic subspace method,and it studies whether the frequency information of the Dongjin Station model can be obtained through the conversion of acceleration signal,in order to verify the effectiveness of the algorithm.(2)The thesis adopts the first-order optimization method of ANSYS,constructs the objective function by the relative error between the real frequency of the structure and the test frequency of the finite element model,in order to update the model.It reduces the frequency error between the real structure and the finite element model after revising,and then the finite element mode reflects the static and dynamic response of the real structure more comprehensively.(3)The hot element is determined by sensitivity analysis of the grid structure rod element and the overall structure column element of Xiangyang Dongjin station by ANSYS.Fatigue damage assessment and life prediction of Xiangyang Dongjin station are carried out.The revised finite element model is taken as the basic model,the wind load and seismic action are applied to it,to extract the stress time history data of structural hot element,and the rain-flow counting method is used to process the data,then the Goodman curve and the Gerber curve are used to process the stress amplitude and the stress mean value obtained by the rain-flow method in order to obtain the equivalent stress amplitude,respectively according to the Miner cumulative damage theory and the revised Miner cumulative damage theory to get the damage degree of rod and column element under the certain period of all kinds of load cycle,and then calculate the residual life of structure hot unit.更多还原