Trigonometric Series Solutions For Bending Behavior Of Composite Beam Bridge With Corrugated Steel Webs

The composite beam bridge with corrugated steel webs is an innovative composite structure,which has been widely spread with advantages of light weight,high prestressed efficiency and excellent workability.The most different feature between the composite beam and conventional prestressed concrete box girder is the significant shear deformation of steel webs.So the shear deformation of corrugated webs is necessary to consider in analyzation of bending deformation of the composite beam.The main conclusions are as follows:1.The bending deformation theories of composite beam with corrugated steel webs has been analyzed.According to the stiffness characteristics,the existing methods are classified as four kinds:Euler beam,Timoshenko beam,the elastic bending method and the effective stiffness method.It is concluded that the theoretical dif-ferences of the four methods are:1)the different assumption of cross-section deformation;2)the different shear rate beared by the corrugated steel webs;3)different key factors.The deflection calculation method suitable for different span-height ratio of the composite beam bridge with corrugated steel webs is concluded through a comparision with FEM results.2.The method of trigonometric series solution has been introduced to consider the shear rotation function of steel webs,the rotation function of concrete flanges and global deflection of composite beam.Based on the principle of minimum potential energy,the bending deformation model for simply supported corrugated steel web girders and cantilever corrugated steel web girders are deduced respectively.The reasonability and serviceability of method of trigonometric series are well verified through comparisons with FEM results,Euler beam and Timoshenko beam.The different span-height ratio are concluded by the method of-trigonometric series of simply supported corrugated steel web girders and cantilever corrugated steel web girders under concentrated and uniformly distributed load.3.The internal forces and stress of simply supported corrugated steel web girders and cantilever corrugated steel web girders under concentrated and uniformly distributed load were analyzed by the method of trigonometric series,and the results were compared with FEM results.The results show that:1)flexural moment of the composite beam is up to ninety-nine percent beared by concrete slabs;2)shearing force of the composite beam is up to eighty-five percent beared by corrugated steel web;3)the cross section deformation of composite beam bridge with corrugated steel webs satisfies the dummy horizontal section assumption;4)the shearing stress of concrete slabs are slight,shearing stress distribution on corrugated steel web is almost uniform along the height of the composite beam.The results gained would provide theory basis for design and calculation of the composite beam bridge with corrugated steel webs.