Civil Engineering Reference
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support restraint, on the response of bridges. Initially, the suitability of dif-
ferent modeling techniques and of elements used to model the primary
bridge components was assessed using simple models for which analytic
solutions are readily available. Based on the studies, it was concluded that
shell elements were adequate to model the bridge deck, and beam and shell
elements are both satisfactory to model the bridge girders. From the dynamic
analyses of two bridges, flexural modes of vibration were found to be highly
sensitive to support restraints and to know how the guardrails were modeled
and less sensitive to the inclusion of bracing and thermal gradients in the
model. The finite element models using extreme boundary conditions were
successful in bracketing the field response. The factors identified from these
analyses were considered in the analysis of the pilot bridge. Different support
restraints and the inclusion of skew and level of composite action in the
model had noticeable impact on both the static and dynamic responses of
the bridge. The results from these analyses were used to assist with instru-
mentation decisions prior to field testing. The general-purpose software
ABAQUS [1.29] was used to perform the finite element analyses. Two dif-
ferent methods were considered to model the bracing members. In the first
method, each part of the bracing assembly was modeled using single linear
beam element (B31), available in ABAQUS element library. The author
suggested that since no member loads were applied to the bracing, the max-
imum order of the deflected shape would be cubic and the shape functions
assumed in case of linear beam element are cubic. Therefore, it should be
able to represent the deflected shape correctly. In the second method, entire
bracing assembly was represented by a single beam element modeled at the
girder centroid. The effective cross-sectional area was calculated by impos-
ing unit displacement in the horizontal direction to the bracing assemblage.
Rigid links were used to connect the bracing with the girder.
composite bridges to resist longitudinal shear forces at the interface of steel
girder and concrete slab. It was shown that since these studs were subjected
to high-cycle fatigue loading due to the growth of traffic and increase in train
speed, the study highlighted the dynamic structural behavior of the shear
studs during train passages. Different fatigue endurance models were
employed for fatigue life estimation. In addition, a parametric study was per-
formed to investigate the effects of different parameters that influence the
fatigue life of shear studs. Finally, a fatigue life-cycle design procedure based
on the train-bridge interaction analysis and the fatigue endurance model was
proposed. A numerical model for a composite bridge with a span of 36 m
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