Experimental And Theoretical Study On Shear Capacity Of Steel Plate Composite Beams

The steel-concrete composite beam has excellent mechanical performance and strong technical and economic advantages in medium and small span bridges.In recent years,driven by the policy of steel capacity reduction,the steel-concrete composite girder bridge has been greatly developed and has a very wide application prospect.However,the shear codes of composite beams in various countries are conservative,and the shear strength field theory of st eel plate beam and the shear strength field theory of composite steel plate beam based on it do not stipulate the calculation of shear capacity of steel plate beam without web shear buckling,which needs to be further improved.Therefore,this paper studies the shear bearing mechanism and failure mode of composite steel plate beam through trial and theoretical research.The main work is as follows:(1)Four loading tests of simply supported steel plate beam in the whole shear process have been completed,and the shear failure mode and failure characteristics are grasped.At the same time,test results such as the bending strain and the in-plane deformation of compression flange and tension flange,the main tensile strain and the out of plane deformation of the web and deformation of loading point are obtained.The ABAQUS model has been established and the simulation analysis results of test steel plate girder were obtained.(2)Based on the theory of tension field,the theory of extended tension field for steel plate beam without elastic shear buckling of web is put forward,and the theoretical value of shear capacity of steel plate beam with and without sh ear buckling is obtained.According to AISC 1997 standard,AASHTO 2012 code,Eurocode 3 and Chinese code GB50017,the shear capacity of steel plate beam is calculated.The comparison results show that the criterion is more conservative,and the accuracy of the extended tension field theory proposed in this paper to calculate the shear bearing capacity of steel plate girder is higher,and it is in good agreement with the test results and simulation results,which can be used in engineering.(3)Four loading tests of simply supported composite steel plate beam in the whole shear process have been completed,and the shear failure mode and failure characteristics have been grasped.At the same time,the corresponding test results are obtained.The ABAQUS model has been established and simulated results of the test composite steel plate beam are obtained.(4)Based on the theory of extended tension field which is suitable for shear capacity of steel plate beam,the theory of extended tension field w hich is suitable for shear capacity of composite steel plate beam is put forward,and the theoretical value of shear bearing capacity of composite steel plate beam is calculated.According to American code,European Code 4,Chinese code and Australian code,the shear capacity of composite steel plate beam is calculated.The comparison results show that the code only considers the shear strength of web conservatively,and the shear strength of composite steel plate beam is significantly higher than that of steel plate beam.The accuracy of the theoretical calculation of shear capacity of composite steel plate beam based on the extended tension field proposed in this paper is higher,and it is in good agreement with the test results and simulation results,which can be used in engineering.