Examples of Finite Element Models of Steel Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 592

Figure 6.28 Elastic lateral buckling mode (eigenmode 1) for the double-track open-
timber floor plate girder railway steel bridge.
to 1.0, the buckling modes are factored by a magnitude of L u /1000, where
L u is the distance between web stiffeners. The factored buckling mode is
inserted into the load-displacement nonlinear analysis of the whole bridge
following the eigenvalue prediction. The developed finite element model
for the whole bridge (see Figure 6.27 ) was used to perform two analyses as
examples in this topic. In the first analysis, the unfactored live load case
was applied, and the deformed shape after load application, load-displacement
relationship, and stress contours were evaluated using the finite element
model as shown in Figures 6.29-6.32 . On the other hand, in the second
analysis, the bridge was taken to overall collapse, and the deformed shape
at failure, load-displacement relationship, and stress contours at failure were
evaluated using the finite element model as shown in Figures 6.33-6.36 .
In Figure 6.29 , the deformed shape of the whole bridge after the appli-
cation of the unfactored live load case is shown. It can be seen that the defor-
mations were in the elastic range. The data obtained from ABAQUS [1.29]
have shown that the von Mises stresses at the maximum stressed fibers at the
top and bottom flanges at midspan were well below the yield stresses. In
Figure 6.30 , the stress (principal stresses in direction 1-1) contours after
the live load application are plotted. It can be seen that the yield stresses were