Analysis Of Shear Lag Effect On Curved Box Girder Bridge Model Under The Action Of Vehicle Load

Curved box girder bridge has extremely extensive application in the transportation, it is not only economical and convenient but also has beautiful appearance. But when the curved box girder bridge is under stress, there exists the phenomenon of shear lag effect, and the bridges that has designed and built without considering the shear lag effect have taken lots of serious security risk.At present, the shear lag effect of box girder under static load has been researched by many professors and scholars. There are few research achievements on the shear lag effect of curved box girder bridge under the effect of dynamic load, especially the most common vehicle load on the box girder. Based on the finite element software ANSYS, this paper analyzes the shear lag effect of simply supported curved box girder under vehicle load.And draws some regularity results.This paper analyzes the impact of structural parameters such as the curved box girder’s radius of curvature,wide span ratio,central angle of curvature and so on,through comparative analysis of box girder structure parameters, combined with the engineering example, selecting a set of box girder bridge design paper with appropriate structure parameters and establish a three-dimensional finite element model with the SOLID65 unit.Next, aiming at the actual situation of automobile market, eighteen groups of vehicle load have been designed and loaded on the inside and outside lane in the finite element model. Not only three kinds of speed such as 10m/s、15m/s、20m/s, but also three kinds of cars are considered.Finally, summarizes the research results obtained in this paper:the shear lag effect in the middle section of box girder is the largest, and descending along the edge of the box girder.It can draw the conclusion that the most unfavorable section of curved box girder under vehicle load is the mid-span section with the shear lag effect. The shear lag effect where the vehicle load affected is severe than other positions.Whether it is loaded on the inside or outside lane,shear lag effect in the roof between the two plates compared to the webs’ is smaller, overall presented M-type.What’s more,at the middle part of bottom plate, the shear lag effect changes little,but the edge portions of Bottom plate is significantly greater than the middle part’s.When the speed of vehicles is between 10m/s to 20m/s, as the speed increases, the shear lag effect on roof box girder is reduced,while the bottom plate’s is first and then decrease.