An efficient modelling approach based on a rigorous cross-sectional analysis for analysing box girder bridge superstructures

Abstract

A novel analysis technique is introduced for efficient modelling of box girder bridge decks. The general three-dimensional equations used to accurately define the deformation of these complex beam-like slender structures are decoupled into a two-dimensional cross-sectional problem and a one-dimensional beam problem through decomposition of the three-dimensional strain field. The two-dimensional cross-sectional problem is solved by a two-dimensional finite element analysis considering in-plane as well as out-of-plane warping displacements of the beam section. This gives an accurate constitutive relationship of the one-dimensional beam problem without making any major assumptions as is often done in usual beam theories. The one-dimensional beam problem is solved by a one-dimensional beam finite analysis and the results obtained are used to recover three-dimensional stress, strain and displacement fields accurately. Numerical examples of box girder bridge deck systems having thin-walled sections are solved by the proposed approach to show its performance.

Buckling behaviour of thin-walled laminated composite beams having open and closed sections subjected to axial and end moment loading

“…Hodges et al [3,10,11] have contributed significantly toward the development of the second approach, which has significant merit in terms of generality, but the 2D finite element analysis needed for the evaluation of cross-sectional stiffness coefficients is a major task. This was experienced and documented in a recent study [12], which is based on a similar approach. On the other hand, the first option (analytical approach), like that presented in Ref.…”

Static and vibration characteristics of thin-walled box beams: An experimental investigation

“…To treat the analysis of thin-walled structures in an efficient yet accurate manner, there exists another approach in which the 3D elasticity problem of the structure is decoupled into a two-dimensional (2D) cross-sectional analysis and a 1D beam problem (Borri and Merlini, 1986; Giavotto et al, 1983; Kashefi et al, 2016). The 2D beam sectional analysis is carried out using a 2D FE discretization where the effects of in-plane warping (sectional distortion) as well as out-of-plane warping are considered.…”

“…The computational efficiency of the method is significantly enhanced when compared to a detailed 3D FE solution. This method has been used to develop a technique for the static and dynamic analyses of thin-walled box girders in a research study carried out by Kashefi et al (2016). However, the model is yet to be validated experimentally.…”

“…Although there have been a number of theoretical as well as some experimental studies undertaken by different researchers for investigating the behavior of straight and curved thin-walled structures, yet only few experimental studies targeted the warping effects and torsional behavior of these structures and the available information is not enough for the validation of the theoretical model developed by Kashefi et al (2016). Therefore, it was essential that experimental investigations be carried out to assess the accuracy of the method confidently.…”

“…To this end, static and vibration tests were implemented on straight as well as curved box beams. Since the theoretical model of the authors has so far been developed for the static and dynamic analyses of straight thin-walled box beams (Kashefi et al, 2016), the experimental results of the straight specimen were used for the validation of this model. However, all the specimens were analyzed using detailed 3D FEM, and the results were compared with those obtained from the experiments.…”