Shear Lag Effects In Some Studies

There are two contents in this paper:one is solve the control differential equation of box girder' s shear lag by DQ method,the other is rules of the shear lag for single-box-multiple-cell box girders.First we introduce what is shear lag and the status of research;We introduce DQ method and use DQ method to solve several bridges in the third chapter;Also we introduce the software-ansys and analysis several bridges by ANSYS in chapter III;In chapter IV we assume several bridge models and get the stress distribution under concentrated load and distributed load;We summarize the paper in chapter V and propose the advancing direction of shear lag.