Study On Shear Lag Effect And Model Test Analysis Of Composite Box Girder With Corrugated Web And Steel Slab

The new type of corrugated web steel bottom plate composite box girder is a new type of structure that fits the concept of green and sustainable development.Its innovation is based on the traditional corrugated web concrete bottom plate composite box girder,using flat steel plates instead of concrete bottom plates to form a new type of steel Mixed combination structure.The structure has the advantages of light weight,large spanning capacity,and no problems such as cracking of the concrete floor.The structure can be produced in factories,which greatly shortens the construction period and guarantees the construction quality.It has obvious technical advantages and broad application prospects.At present,Gansu Province is the first to promote the use of this new type of structure,and it has been applied to the bridges of various expressways in Gansu Province.Based on the previous research results,this paper studies the shear lag effect of the new type of corrugated-web-steel-slab composite box girder through theoretical derivation,experimentation,and finite element simulation.The construction provides certain theoretical and technical support.The research content of this paper mainly includes:(1)Theoretical analysis uses the spline finite point method to obtain the spline discretization stiffness matrix by establishing the spline discretization total potential energy functional,so as to solve the stress distribution of the top and bottom of the composite box girder with corrugated webs and steel bottom plate.Further obtain the box girder shear lag coefficient;(2)Fabricate test beams for composite box girder with corrugated webs and steel bottom plates,arrange sensors,and perform static tests on them to obtain the strain and deflection values of the mid-span section.On this basis,the correctness of the theoretical analysis is verified;(3)In the finite element simulation,the multi-condition finite element numerical simulation was carried out to obtain the change law of the shear lag coefficient of the top and bottom plate of the composite box girder with corrugated web and steel bottom plate.Comparing the three,it is obtained that the stronger the constraint conditions,the greater the influence on the shear lag effect.(4)Further study the change law of the shear lag coefficient of the flat steel web composite box girder,and compare and analyze the relationship between the finite element model of the flat steel web composite box girder,the corrugated web composite box girder and the deflection of the test beam.It is obtained that the corrugated web steel bottom plate composite box girder has the influence of the wrinkle effect,which reduces the rigidity of this type of structure.This thesis studies the shear lag effect of composite box girder with corrugated webs and steel bottom plate.Through theoretical analysis,model test and finite element simulation,it provides references for further perfecting the theoretical analysis,design and construction of this type of structure.