The Theoretical And Experimental Analysis Of Shear Lag Effect Of Open Spandrel Composite Box Beams

In recent years, with the speeding of the national infrastructure construction, bridgeconstruction leaps and bounds, especially some new types of composite structures. becausethe open spandrel composite box girder with light-duty, assembling, the beautiful andconvenient construction advantages is widely used. This article is based on the wing plate ofsingle box and single chamber open spandrel composite box girder about combination theshear lag effect problems.First expounds the definition of stress analysis, the shear lag effect of box girder, analysismethod and theoretical system, and then according to the characteristics of open spandrelcomposite box girder, assumes that upper plate, bottom plate and the cantilever plate withdifferent shear lag longitudinal displacement differential functions, longitudinal displacementcosine function distribution along the width direction, using the energy variational principleis established considering Timoshenko shear deformation about the single box single room ofthe open spandrel composite box girder combination control differential equation andboundary conditions, solved the differential equation of the closed solution, concentrated loadand uniformly distributed load is presented under the action of the simply supported beam andcontinuous beam under the action of uniformly distributed load calculation formula of shearlag, using the method of superposition the three spans typical continuous beam of shearlag coefficient under the concentrated load and uniform load is given. having deduced theopen spandrel composite box girder shear lag of control differential equation considering loadtransverse position, ZHANG Shi duo called it as generalized negative shear lag theory.taking the simply supported beam as an example, discussed the load transverse functionposition of shear lag effect and the influence of deflection, added shear lag complete theorysystem of open spandrel composite box girder.In view of corrugated steel web can not resist moment，bringing the corrugated steelweb composite box girder into the open spandrel composite box girder system. Taking thecorrugated steel web composite box girder as an example, using the large-scale generalfinite element software ANSYS to establish space3D model of simply supported beam withcorrugated steel web plate that the calculation span is6m to test and verify the shear lagtheory considering the transverse function position. Made a model for the (3+3) m spanacross two corrugated steel web composite continuous beam, through model test loadingmethod of two span continuous beam under uniformly distributed load of the shear lag theoryis verified.Through single box and single chamber open spandrel composite box girder wing plate ofshear lag effect and the mechanical characteristics, using the corrugated steel web composite box girder for validation, to recognize single box and single chamber openspandrel composite box girder which lay a theoretical foundation for the mechanicalproperties of composite box girder, for designing and building on the open spandrelcomposite box girder to provide theory support, which has the reference value.