Refined analysis of curved thin-walled multicell box girders

The generalized Vlasov's thin-walled beam theory was combined with the finite element technique to develop a new curved thin-walled multicell box girder finite element which can model extension, flexure, torsion, torsional warping, distortion, distortional warping and shear lag effects. For multicell box girders, several distortional modes were introduced to describe the complete distortional behaviour of the cross-section. Interaction between the longitudinal and transverse deformations of the box girder was also accounted for. The element is one dimensional, it has three nodes and employs the conventional polynomial shape functions. For modelling flexure, Timoshenko beam theory was used to take account of shear deformations. A computer program was developed based on the proposed element for the analysis of single and multicell curved box girder bridges. Numerical examples are presented to demonstrate the accuracy and efficiency of the proposed element. Compared to the standard finite element method, the proposed method needs substantially less computer time, memory and input data. The output is also in a form which can be used in design without further manipulation.