Examples of Finite Element Models of Steel Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 557

the bending moments at the supports of the ribs provided by the floor beams.
In the study [ 6.5 ] , the authors proposed a method accounting for the shear
deformation in the floor beam. The validity of the proposed method was
checked by full finite element calculation using shell elements that inher-
ently comprise shear deformation. The authors developed a finite element
model using four-node Mindlin shell elements. The floor beam model was
subjected to a 100 kN concentrated load at midspan. Felkel et al. [ 6.8 ] eval-
uated the behavior of bridge girders made of high-performance steel (HPS
70W). The basis for the study was a three-span replacement bridge utilizing
HPS 70W girders within all negative moment regions. The study consisted
of in situ measurements, experimental tests, and analytic investigations.
Three half-scale specimens were tested under monotonic and cyclic loading
conditions. The study [ 6.8 ] presented results from analytic and experimental
investigations highlighting the strength performance of the girders. Data
obtained from laboratory tests were used to validate computer models for
design evaluations. Parametric studies were performed using the models.
The findings of the study indicated that improved structural performance
may be obtained when location of bracing was optimized and fabrication
imperfection tolerances were minimized. The measured nonlinear material
model was adopted in the finite element analysis. Small fabrication and geo-
metric imperfections within tolerances observed in the tests were not ini-
tially simulated. Subsequently, imperfections were simulated by applying
a small lateral pressure along the entire length of the compression flange.
Galvin and Dominguez [ 6.9 ] presented a theoretical and experimental
research work on a cable-stayed bridge. Full-scale tests were carried out
to measure the bridge dynamic response. The experimental program
included the dynamic study for two different live load conditions: the bridge
with one-half of its lanes loaded with cars and the bridge unoccupied. Modal
parameter estimations were made based on the acquired data. Ten vibration
modes were identified in the frequency range of 0-6 Hz by different tech-
niques, two of these modes being very close to each other. The traffic-
structure interaction was also studied. Experimental results were compared
with those obtained from a 3D finite element model developed in this work.
The authors applied a damage identification technique to determine the
integrity of the structure. The developed finite element model was a 3D
model developed for the numerical analysis of the structure using as-built
drawings of the bridge and some double-check in situ measurements. Modal
analysis was carried out using ANSYS [ 6.10 ] . The arch, supports, and the
internal stiffener were represented as two-node beam elements (BEAM44)