Study On Shear Lag Effect Of Curved Continuous Steel Box Girder And Analysis Of Mechanical Behavior Of Structure

Along with the city road continues to expand,because of the need of city construction,a large number of curve bridge.The rapid rise of the curved bridge under torsion coupling with stress is very complex,and the box girder due to its excellent bending and torsional properties,and became widely application in curve bridge.The curve bridge is also an important.The phenomenon of stress,the shear lag effect.If ignoring the shear lag effect in the design,it will bring great impact to the stability of the structure.At present,the research on shear lag effect of straight box girder bridge has been more mature,and the study for the shear lag effect of the curved box girder bridge is still need to be studied further.Most scholars study the curve of shear lag effect in box girder,is based on the geometrical parameters of the structure and characteristics of cross section,but the stress characteristics of curved bridge are coupled,form and position of load on the shear lag effect Also have a great impact.By using the energy variational method to deduce the curved box girder considering restrained torsion and torsion strain energy,torsion shear lag coefficient expression of warping strain energy,and in Suzhou City,Central Expressway high section of a three span curved continuous steel box girder bridge as an example,the application of finite element analysis software ANSYS to establish finite element model for bridge model in eccentric load under symmetrical load at different longitudinal position and different lateral positions under the analysis of the distribution and change of shear lag coefficient of cross section,and draw the shear,bending moment and torque value,thus obtains the quqiao flexure,shear,torsion effect on the shear lag effect finally,the shear lag effect of straight box girder and the curved box were compared.It can be seen from the results,the effect of different load position,the transverse distribution of curved box beam shear lag coefficient of volatility,has been experiencing the positive shear lag switch;load lateral deflection,shear lag effect is always in the vicinity of load fluctuation;load longitudinal displacement of the load section the shear lag effect is bigger;bending,shear,torsion effect on the shear lag effect has great influence,the eccentric load torque change in shear and moment more obvious influence on the shear lag effect can not be overlooked;compared with the straight line box girder,the lateral distribution of curved box girder is not symmetricline box girder and the eccentric load is diminishing.