FEM Models of Multiple-Cell Steel Box Girder Bridges for Design Practice

Recently, it became a common practice to use FEM analysis for structure designs. Since beam elements are simple and easy to use in FEM model, steel box girders of a bridge are normally modeled with beam elements. In this study, a multi-cell steel box girder composite bridge was analyzed with different FEM models, i.e. Shell-Element-Model which is supposed to give the best results and Beam-Element-Model which is commonly used in the practice. And also proposed is an improved Beam-Element-Model, which is also easy to build up, but supposed to give almost as good results as Shell-Element-Model. The FEM analysis results of the models were compared each other. The Beam-Element-Models showed no big differences to the Shell-Element-Model in stresses and deflections. However, the use of the Improved Beam-Element-Model is required to get appropriate values of reaction forces of the supports.