Analysis on Shear Lag Effect of Super Wide Composite Beam
The ratio of width to height of super wide composite beams is very large.The mechanical properties of super wide composite beams under bending moment are different from those of ordinary beams.Up to now,there is no systematic formula for the effective width of super wide beams in the specifications.In order to further study the characteristics of uneven distribution of normal stress caused by shear lag effect of superwide composite beam under bending moment,taking Shenshan Bridge as the engineering background,ABAQUS finite element software has been used to establish a 52.5 m space shell element finite element simply supported beam system model of 15 mid-span cross beam sections and a space bar element full bridge model by Midas civil.The distribution of normal stress and shear lag coefficient of the roof,floor and 1/4 cross-section roof of the mid-span section under the action of dead weight,lane load,crowd load and suspender force have been studied.The results have shown that there is obvious shear lag effect in the structure of super wide composite beams under load.At present,the safety factor of the effective width calculation formula in the specifications is 1.21~1.63 times higher than the actual one.
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