Research On The Stability Of Steel Plate Girder Bridge Based On The Whole Space Analysis

In recent years,the country's infrastructure is developing rapidly,especially in railway and highway construction,we see more and more steel structure put to use in practical engineering,the bridge structure tends to be diversified,more advanced and reasonable design level and construction technology.Among them,the steel plate girder bridge is accompanied by the Chinese railway all the way to witness the rapid development.The design concept and construction level of steel plate beam which maturity is also near perfect.But the stability of steel plate beam as a prominent problem in the process of bridge design,if not treated properly will cause serious accidents,steel overall lose stability when the beam will produce lateral bending and torsional deformation on the macro level.The girder and deck consists of an open framework,so in order to enhance the stability of performance,provide sufficient strength,so set the humeral plate between the beam and the main beam,which is from the structure to make up for the stability of longitudinal brought.However,the structural strength of the humeral plate and the stability of the structure itself need further discussion.Furthermore,study on stability of steel plate girder bridge bearing under the traditional usually because of the complexity of the structure,the overall stability and local stability are divided into two parts which are calculated,now due to the development of finite element technology,it can put through steel plate girder bridge completely as a whole stability.Writing ideas are as follows:First of all,through reading the classical teaching materials related to the steel plate bridge,the highway,railway specifications and related literature.In this paper,the calculation method of stability of steel plate girder bridge and relevant research contents are summarized.Summarize the local and overall stability of the highway steel plate girder bridge and the railway steel plate girder bridge respectively.Secondly,through finite element books,summed up the finite element software MIDAS on plate finite element equation,plate unit load method,result analysis unit plate,boundary condition and constraint equations between elements,application of finite element method for elastic buckling analysis of the contents of the structure,so as to provide a theoretical basis for numerical analysis of troughsteel plate girder bridge using finite element method.Then by using numerical calculation method,in order to ensure that the structure in global instability does not appear before the local instability,according to the rules for the local stability of the structure,further analysis through steel plate girder bridge the detail structure influence on local stability of structure produced in the standard range,which could meet the standard finite element the local stability of the model.Finally,to meet the requirements of the finite element model respectively from the two aspects of humeral plate and no humeral plate overall stability analysis,explore the macro loss of overall structure stable mode buckling loads,and structural specification of the overall stability calculation,the critical value is calculated from the two aspects of the search for differences overall,the stability problem can study through steel plate girder bridge.The conclusions are as follows:(1)The finite element analysis for steel girders with humeral plate under the two conditions after the data show that when the addition of humeral plate for through steel plate girder bridge that only by girder and deck together constitute an open framework for further with strong stability,it can be a top flange of the girder supporting role,to ensure the stable performance of the flange plate;the deflection can play a role in cross link and reduce or prevent the girder.From the through steel plate girder bridge has no map of the two kinds of buckling modes of brachial plate can be confirmed,and the corresponding critical load can bear the value with a more obvious improvement,never add humeral plate at 238.78 kN,adding to the brachial plates after 306.51 k N.The critical load value is raised by 28%.(2)In the overall stability calculation of the through steel plate girder bridge with an added humeral plate,the limit value calculated from the railway code is 270 MPa,while the maximum bending stress of the whole bridge obtained by the finite element calculation is 279.52 MPa.Comparing the two,we can know that the overall stability of the calculation according to the railway code checking is conservative,and can be safely applied in the relevant calculation of the actual project.The specification for the overall stability of the structure is approximate calculation method,so the results obtained by the finite element analysis of the concrete structure,further validation of the specification is suitable for through steel plate girder bridge overall stability checking.(3)The use of the highway standard,lateral torsional buckling strength is calculated as:,according to the type of finite element calculation results of plate girder bridge bearing has humeral plate,and on the basis of 2.2.1 type(2.36)is the critical moment for flexural torsional buckling.As a result,compared to the highway code,the calculation value is small,but it is within the standard.Comparing the two values,we can know that the overall stability obtained by the highway code checking is basically conservative,and can be safely applied in the relevant calculation of the actual project.