Dynamics response of thin-walled rectangle box girders considering shear lag effect

In order to study dynamic characteristics of a thin-walled box girder, considering the shear deformation and shear lag effects, the energy variation principle was used to establish the governing differential equations and the corresponding natural boundary conditions about the three generalized dynamic displacement functions w(x, t), u(x, t), θ(x, t). The closed form solutions to the generalized displacement functions were obtained which discovered the dynamic law of the thin-walled box girder. An example is analyzed to compare the finite shell element solutions with the analytical solutions, the proposed approach is testified.