Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 32

The behavior of curved composite steel I-shaped plate girder bridges was
investigated by Chang and White [ 1.58 ] . The authors considered different
parameters affecting the composite bridge modeling including girder web
distortion, cross frames, support and load height, and displacement compat-
ibility between the girders and slab. In the study, web distortion effects were
investigated and an approximate approach using open-section thin-walled
beam theory for the steel I-girders was proposed. Different analysis
approaches including line girder analysis, V-load method, grid methods,
and general finite element methods for analysis of curved I-girder bridge
structural systems were highlighted. The investigated plate girders were hor-
izontally curved bridges subjected to coupled torsion and bending. It was
shown that the plate girder behavior in these bridges involved significant
web distortion, which caused additional lateral displacements and lateral
bending stresses at the girder bottom flanges. The study showed that a gen-
eral 3D analysis using shell elements for the slab and for the girder webs and
3D grid models using open-section thin-walled beam theory for the plate
girders were recommended for efficient modeling of the bridges. However,
the study suggested approximate approaches for simulating the composite
I-shaped plate girder web distortion effects using 3D grid methods. It was
found that when using an open-section thin-walled beam element for the
bridge plate girder and either shell elements or a beam grid system for the
slab, a rotational release must be placed between the slab and the top flange
of the I-girders in order to compensate the web distortion effects. It was also
found that when using an open-section thin-walled beam element for the
combined slab and steel plate girder via an equivalent composite plate girder
cross-sectional model, the contribution from the slab to the St. Venant
torsional constant J was suggested to be neglected. In addition, the lack of
consideration of the web distortion effects results in a significant underesti-
mation of the girder bottom flange lateral bending stresses. The authors have
compared results from a full-scale composite I-shaped plate girder bridge
against the results of the 3D grid models.
Structural performance of bridge decks with high load resistance capacity
as well as high fatigue strength is a current research topic. Ahn et al. [ 1.59 ]
conducted tests to investigate the fatigue behavior of a new type of
steel-concrete composite bridge deck. The proposed composite bridge deck
consisted of corrugated steel plate, welded steel ribs, headed stud shear con-
nectors, and RC filler. Fatigue tests were conducted under a four-point
bending test with four different stress ranges in constant amplitude. A total
of eleven fatigue specimens were subjected to cyclic loading to evaluate the