Keywords: finite-strip method, geometric nonlinear analysis, box girders, shear-lag effect, automatic visualization.

In folded-plated structures, the webs and flanges are interconnected so that relative displacements cannot occur between them. Shear flows are developed between the webs and flanges, causing shear stresses and deformations and the corresponding warping of the flange plates [1,2]. This phenomenon leads to a non uniform distribution of the longitudinal normal stresses across the flange width.

This paper deals with the classical and nonlinear shear-lag effects on stress redistribution in box girders using the finite-strip method (FSM). It is in fact an exact method because it considers the box girder including all details in the actual form as an assembly of plate elements forming a real spatial system. The use of the uncoupled FSM method to the first-order phenomenon, called 'shear lag' results in a considerable saving of computer time over the finite-element method [3].

Noted however, that govern further progress in the design of box-girders, is that of the interaction which exists between shear lag and post-critical plate buckling in the longitudinally compression flanges of these structures. This problem is geometrically nonlinear and cannot be treated further in analysis by using effective-width factors.

In the research presented the computation of the maximum longitudinal stresses and deformations using the harmonic coupled finite-strip (HCFSM) formulation is investigated. The HCFSM, which satisfies the von Karman plate equations in the nonlinear elastic range, leads to the coupling of all harmonics [4].

However, sequential execution of the developed HCFSM software is very slow and produces a great amount of numerical results. So it is necessary to parallelize this algorithm and to offer automatic visualization of numerical results. Combination of two ways of parallelization (CUDA, MPI) constitutes a hybrid parallelization approach. Interpretation of numerical results is much easier if it is supported by data visualization that offers different graphical representations of incremental displacements and internal forces [5].

1

A.C. Scordelis, "Analytical Solutions for Box Girder Bridges",Conference on Developments in Bridge Design and Construction, Cardiff, UK, 1971.

2

V. Krístek, "Theory of Box Girders", John Wiley and Sons, 1979.

3

Y.K. Cheung, L.G. Tham, "Finite strip method", CRC Press LLC, 1998.

4

D.D. Milašinovic, "The Finite Strip Method in Computational Mechanics", Faculties of Civil Engineering, University of Novi Sad, Technical University of Budapest and University of Belgrade, Subotica, Budapest, Belgrade, 1997.

5

P. Rakic, D.D. Milašinovic, Z. Zivanov, M. Hajdukovic, "MPI-CUDA Parallelisation of the Finite Strip Method for Geometrically Nonlinear Analysis", in B.H.V. Topping, P. Iványi, (Editors), "Proceedings of the First International Conference on Parallel, Distributed and Grid Computing for Engineering", Civil-Comp Press, Stirlingshire, UK, Paper 33, 2009. doi:10.4203/ccp.90.33

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £125 +P&P)