Modeling And Simulation On The Vibration Of Railway Superstructure With Considering Of The Connected Details

In recent years,the development and utilization of subway stations and parking spaces has become a hot spot to improve land use efficiency and economic benefits.However,because of the long-term vibration environment of such railway superstructures,these vibrations affect the health of people living in these buildings.The vibration generated by the orbital operation will affect the normal use of the building,so a finite element model that can accurately simulate its vibration performance is one of the indispensable prerequisites for the design of such building structures.At present,the finite element model of the building is similar to that of ordinary buildings.This model neglects the influence of the connection between the railway superstructures and the lower structure on the dynamic characteristics of the superstructure.When this kind of model is used for the simulation of vibration characteristics,the results are often not ideal.Therefore,this paper first considers the local details of the connection between the subway superstructure and the lower part,and establishes the engineering model of using the spring element to simulate the key constraint parameters.The boundary parameters of the six degrees of freedom in the critical connection are discussed.Secondly,according to the relevant engineering drawings,the connection between the subway superstructure and the lower structure is based on its detailed features to establish a multi-grid model containing local fine simulation,and the use of the measured information on the two The finite element model established by different methods is modified.Finally,based on the modified multi-grid finite element model,the effective and feasible vibration control method is discussed.Specifically,the research work and the main achievements of this paper are as follows:Aiming at the need of finite element analysis of structural vibration performance of subway superstructure,combined with the different connection forms of structure has great influence on its vibration characteristics,we choose the upper part of the building and the lower part of the track The connection between the parts of the body as a key research object.Based on the actual engineering,the engineering model of using the spring unit to simulate the key constraint parameters of the key connection is established,and the rigid pile between the middle and lower part of the project is simplified.On the basis of validating the validity of the model,the source of the error is analyzed,and the constraint stiffness of the critical connection of the different model is simulated by modifying the stiffness coefficient of the spring element.The constraints of the six degrees of freedom in the critical connection are analyzed The results show that the constraint stiffness parameters of the critical vertical plane free-range direction have the greatest influence on the vibration noise of the building,and the influence of the restraint stiffness in the other degrees of freedom is relatively small Ignorable.Based on the theoretical framework and the implementation of finite element software,the connection method of different types of elements in finite element model is discussed.Based on the engineering model,a multi-grid finite element model of key local modeling of key connections is established.The solid elements are used to simulate the local connection of concrete materials.The beam elements are used to simulate the steel bars.The part that connects the local fine simulation is connected to the rest of the model.After verifying the validity of the multi-grid model,the simulation results of the model and the engineering model are compared with the measured values.According to the results of sensitivity analysis,two finite element models established by different methods are modified and validated.The results show that the two models can obtain better simulation results.Under the premise that the model calculation efficiency is not very different,the simulation results of the multi-grid model are closer to the measured values than the engineering model.The finite element model of the subway roof structure is not only the part selected as the objective function closer to the measured value,but also the error in the part of the simulation result that is not selected as the objective function is also reduced.After comparing the measured vibration noise with the national standard limit,it is found that the measured vibration noise will slightly exceed the appropriate limit in the national standard when the rigid pile connection between the subway cover and the lower part is connected.After investigating the current commercially available seismic support principle,it is found that the ordinary seismic support does not apply to the damping design of the subway roof structure,but it can use the vertical anti-vibration structure of the three-dimensional seismic(vibration)The connection of the top cover is partially optimized for vibration reduction.Based on the multi-grid model of the subway cover,the Mooney-Rivlin model is used to consider the super-elastic properties of the rubber material,and the local anti-vibration performance optimization model is established.The The results show that it is reasonable and feasible to reduce the vibration and noise of the building on the key structure by using the rubber block to reduce the vibration noise of the building.In summary,practical simulation results can be obtained using the two kinds of finite element models considering the connected parts.The key connection between the subway superstructure and the lower structure is carried out by using the rubber layer Vibration design can achieve significant results.The work for the subway building vibration performance simulation and vibration design provides a new way of thinking and methods.