Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 4

of forces and stresses in the component members, which is the target of the
nonlinear finite element modeling approach detailed in this topic. In addi-
tion, in case of steel-concrete composite bridges, if the slab cracks under
heavy traffic loads or the steel beam yields or buckles, it becomes extremely
important to know the location of failure, the postfailure strength of the
component that has failed, and the manner in which the forces and stresses
will redistribute themselves owing to the failure. Once again, traditional
simplified analyses cannot account for these complex failure modes because
no interaction between bridge components was considered. The finite ele-
ment modeling approach aimed in this topic will capture all possible failure
modes associated with steel-concrete composite bridges. It should also be
noted that while simplified design methods have been developed to predict
the ultimate capacity of steel bridges or their components, none of these
methods adequately predicts the structural response of the bridge in the
region between design load levels and ultimate capacity load levels. There-
fore, the proposed finite element modeling approach will reliably predict
both the elastic and inelastic responses of a bridge superstructure as well
as the structural response in the region between the design limit and the ulti-
mate capacity. Another complex issue is the slip at the steel-concrete inter-
face in composite bridges that occurs owing to the deformation of shear
connectors under heavy traffic loads. This parameter also cannot be consid-
ered using simplified design methods and can be accurately incorporated
using finite element modeling. The aforementioned issues are only examples
of the problems associated with modeling of steel and steel-concrete com-
posite bridges. Overall, this topic provides a collective material, for the first
time, for the use of finite element method in understanding the actual
behavior and correct structural performance of steel and steel-concrete com-
posite bridges.
Full-scale tests on steel and steel-concrete composite bridges are quite
costly and time-consuming, which resulted in a scarce in test data for differ-
ent types of bridges. The dearth in the test data is also attributed to the con-
tinuing developments, over the last decades, in the cross sections of the
bridges and their components, material strengths of the bridge components,
and applied loads on the bridges. Therefore, design rules specified in current
codes of practice for steel and steel-concrete composite bridges are mainly
based on small-scale tests on the bridges and full-scale tests on the bridge
components. In addition, design rules specified in the American Specifica-
tions [ 1.23-1.25 ], British Standards [ 1.26 ] , and Eurocode [ 1.27 , 1.28 ] are
based on many assumptions,

limitations, and empirical equations. An