Study On Shear Lag Effect Of Continuous Beams With Corrugated Steel Webs Whose Warping Displacement Function Is Catenary

The growth of urban traffic has put forward more stringent requirements on urban viaducts,which require light weight,wide box girder,easy construction,economical and beautiful bridge type,and single-box single-cell corrugated steel web box girder is connected in the transverse direction.The resulting wide-box continuous girder bridge can well meet the above requirements.Its single-box single-chamber has a light weight and can use profiled steel plates as templates to realize the rapid pouring of the secondstage concrete deck without brackets.However,as the width of the box girder increases,the shear lag effect becomes more obvious.If it is not taken seriously,it may affect the safety of the bridge.Therefore,this paper uses theoretical research and finite element analysis combined with actual engineering to study the shear lag effect of continuous beams with corrugated steel webs.The details are as follows:(1)The definition of shear lag effect and effective distribution width is introduced,the research methods of box girder shear lag theory are summarized,and the research status of shear lag effect of composite beams with corrugated steel webs is described.(2)Taking the catenary as the warping displacement function,the energy variation method is used to derive the differential equation of the single-box single-chamber box corrugated steel web beam,and the simply supported beam and continuous beam are deduced under the action of concentrated load and uniform load.The formula for solving the shear lag coefficient;at the same time,a finite element model of a single-box singlechamber continuous beam with corrugated steel webs is established to analyze the shear lag coefficients of different sections under different loads.The results show that the shear lag coefficient of the top plate is the largest at the junction of the top plate and the web,and the shear lag coefficient of the bottom plate is the largest at the edge of the bottom plate.The maximum shear lag coefficient under uniform load is less than the maximum under concentrated load.Shear lag coefficient.Taking a single-box single-chamber continuous beam as an example,the shear lag coefficient obtained by the finite element method is compared with the shear lag coefficient obtained by the energy variation method.The maximum difference is 0.053,which verifies the correctness and correctness of the theoretical derivation in this paper.The effectiveness of finite element modeling.(3)The finite element software ANSYS was used to analyze the shear lag effect in different construction stages when a four-chamber continuous beam with corrugated steel webs adopts simple support and variable continuous construction.The results show that the shear lag of the main beam is lagging after the prestressing of the main beam is completed.The efficiency coefficient is the smallest.Through the analysis of the shear lag effect of the two construction methods of simply supported variable continuous without brackets and full building brackets,the results show that the shear lag coefficient is smaller when the full building brackets are used than when the simple supported variable continuous constructions without brackets are used.(4)Combined with the finite element model of the single-box single-chamber continuous beam with corrugated steel webs,the factors affecting the shear lag effect of continuous beams with corrugated steel webs under concentrated load and uniform load are analyzed.The results show that: whether it is concentrated load or uniform load Distributed load and width-span ratio are the main factors affecting the shear lag effect of continuous beams with corrugated steel webs.With the increase of the width-span ratio,the shear lag coefficient increases rapidly.When the width-span ratio increases from 0.2to 0.9,the shear force The lag coefficient increased by 30.45%.