Finite Element Analysis of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 500

Therefore, it is recommended in this topic to use guided meshing where the
modelers apply the aforementioned fundamentals in developing the finite
element mesh using current software. In this case, automatic meshing soft-
ware can be of great benefit for modelers.
5.4 MATERIAL MODELING OF THE BRIDGE COMPONENTS
5.4.1 General
As mentioned previously, if we classify steel and steel-concrete composite
bridges according to the materials of construction, we will find mainly
two materials. The two materials are the structural steel and concrete, which
are briefly highlighted in Chapter 2 based on the information presented in
current codes of practice. In this section, it is important to detail how the
stress-strain curves of the two main components are accurately incorporated
in finite element modeling. It should be noted that there are other steels used
in bridges, which may have higher ultimate stresses compared with structural
steels such as steels used in bearings, shear connectors, bolts, prestressing ten-
dons, and reinforcement bars. However, these can be incorporated in the
same way as structural steels. Also, it should be noted that bridges may have
different other materials such as stainless steels, aluminum, and cold-formed
steel. These also can be treated following the same approach as the structural
steel as previously presented in [ 5.1 ] . However, it is recommended in this
book that other materials used in bridges of special nature should be inves-
tigated individually and incorporated differently in the model such as
advanced composite laminates, materials used in bearings (elastomeric mate-
rials), and dampers. In the coming sections, the author aims to provide a
good insight regarding material modeling of structural steel and concrete
as adopted in most available general-purpose computer programs, with
ABAQUS [1.29] presented as an example.
5.4.2 Material Modeling of Structural Steel
Structural steel members have linear-nonlinear stress-strain curves, as shown
in Figure 2.3 . The engineering stress-strain curves are determined from ten-
sile coupon tests or stub column tests specified in most current international
specifications. Although the testing procedures of tensile coupon tests and
stub column tests are outside the scope of this topic, it is important in this
chapter to detail how the linear and nonlinear regions of the stress-strain
curves are incorporated in the finite element models. The main important