3D FE modelling of composite box Girder Bridge

Abstract

The complexity nature of composite box girder bridges makes it difficult to accurately predict their structural response under loading. However, that difficulty in the analysis and design of composite box girder bridges can be handled by the use of the digital computers in the design. An intricate geometry such as that of composite box girder bridges can be facilely modelled using the FE technique. The method is also capable of dealing with different material properties, relationships between structural components, boundary conditions, as well as statically or dynamically applied loads. The linear and nonlinear structural response of such bridges can be predicted with good accuracy using this method. A major interest in this paper is to perform three-dimensional FE analyses of composite box girder bridge to simulate the actual bridge behaviour. ANSYS FE package is used to develop the models which offer different element types and physical contact conditions between concrete deck and steel girder. Predictions of several FE models are assessed against the results acquired from a field test. Several factors are considered, and confirmed through experiments especially full shear connections which are obviously essential in composite box girder. Numerical predictions of both vertical displacements and normal stresses at critical sections fit fairly well with those evaluated experimentally. The agreement between the FE models and the experimental models show that the FE model can aid engineers in design practices of box girder bridges.