Nonlinear Material Behavior of the Bridge Components - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 102

Orthotropic reinforcing bars in the concrete slab were modeled by four lay-
ered elements as a smeared layer with constant thickness. The thickness of
the smeared layer was equal to the area of each bar divided by the bar spac-
ing. The finite element program ABAQUS was used to analyze this model.
The use of rigid links shows that the interaction between the steel beam and
concrete slab is complete and there is no slip between the shear connectors,
which is not true and has been rejected by many researchers. Gattesco [ 2.81 ]
studied numerically the nonlinear behavior of composite steel-solid slab
beams with deformable shear connection. The numerical procedure
accounted for the nonlinear behavior of concrete, steel, and shear connec-
tor. The finite element package COBENA was used in the analysis. The
steel beam and the concrete slab were modeled by using beam-type elements
that have four nodal points with 3 degrees of freedom per node (horizontal
and vertical displacements and rotation in the x-y plane). The interface
between the steel beam and the concrete slab was modeled by two horizon-
tal springs. The uplift of the concrete slab with respect to the steel beam and
the buckling effects of the steel beam were neglected. The model was ver-
ified by comparing the finite element solutions with the experimental work
of Chapman and Balakrishnan [ 2.82 ]. The author found good agreement
between numerical and experimental results and concluded that this model
can be used for extensive parametric studies on composite beams with com-
plete or partial shear connection.
Kwak and Seo [ 2.83 ] modeled the behavior of composite girder using
the finite element method. The aim of the study was to predict the long-
term behavior of composite steel-solid slab girders in bridges. A 2D beam
element that has 3 degrees of freedom (two translations and one rotation)
was used in the analysis to represent the steel beam and the concrete slab.
Material nonlinearities have been taken into consideration. The elements
were divided into imaginary layers to describe the material properties with
the assumption that plane sections remain plane to represent the linearity in
the strain distribution on any section at any time. The load-slip characteristic
of the stud has been neglected in the analysis, and perfect interaction has
been assumed between the steel beam and the concrete slab. The finite ele-
ment method was used in the modeling of steel-solid composite beams
curved in plane by Thevendran et al. [ 2.84 ] . The numerical model was used
to verify the experimental testing aimed by the authors to study the ultimate
load behavior of these composite girders. The finite element software, ABA-
QUS, has been used in the analysis. Full composite action between steel
beam and concrete slab was assumed. Figure 2.25 shows a typical finite