Fatigue Cumulative Damage Assessment And Life Prediction Of Railway Station Buildings

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.