Realization And Engineering Application Of Influence Surface Based On Finite Element Software ABAQUS

With the increase of traffic flow,the width-span ratio of modern bridges is also increasing,and the structure of bridges is becoming more and more complicated.Vehicle load is one of the important live loads undertaken by the bridge structure.At present,the analysis of live load effect of bridge structure is mainly based on the theory of transverse load distribution.The analysis of spatial structure is transformed into plane analysis of two orthogonal directions.It is to find an approximate influence surface within a certain error range instead of the precise influence surface.Although this method has the advantages of clear concept and simple calculation,it often brings great errors to the analysis of complex structures.In view of this,the force analysis based on the influence surface of the spatial structure model can not only obtain the most unfavorable influence value of any part of the bridge,but also better reflect the stress state of the bridge structure.Based on the relevant theory,this paper calculates the influence surface and carries out load analysis of continuous box girder bridges.Initially,the finite element model of continuous girder bridge is established by using finite element software ABAQUS.And the static stress calculation method of unit moving load is used to analyze the stress response value of key nodes and the vertical support reaction force response value of each bearing position.In the next place,based on the results of finite element analysis,the static response influence surface of key parts is drawn by MATLAB software,and the influence surface graphics are compared,analyzed and theoretically verified.Afterwards,based on the superposition principle,the influence surface loading program is compiled by MATLAB and Visual Basic language,loading analysis of the influence surface is carried out,and the most disadvantageous load position and the most disadvantageous response value of the key nodes are solved.Simultaneously,according to the calculated most disadvantageous position of the load,the loading calculation is carried out directly in ABAQUS to verify the accuracy of the loading program of the influence surface.Besides,comparing with the results of the grillage model,the spatial effect of the influence surface calculation is verified.Finally,based on the concrete damaged plasticity model,the finite element software ABAQUS is used to calculate the nonlinear force of the continuous beam bridge,and to guide the design work,the stress field distribution under different load conditions is analyzed.