Examples of Finite Element Models of Steel Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 581

generally good agreement was achieved between experimental and
numerical relationships. The ultimate failure load observed in the test
[ 6.27 ] was 1752 kN at a deflection of 5 mm, while the ultimate failure load
predicted from the finite element analysis was 1742 kN at a deflection of
5.3 mm. The finite element failure load was 1% lower than that observed
in the test.
6.5 FINITE ELEMENT MODELING AND RESULTS
OF EXAMPLE 3
The third example presented in this chapter is for a full-scale built-up
I-section plate girder steel bridge tested under bending by Felkel et al.
[ 6.8 ] . The plate girder was a part of an experimental program investigating
the effect of lateral bracing on the strength and behavior of the bridges. The
plate girder is denoted in this study as (T3). The small-scale plate girder was
SS and had an overall length of 13.411 m as shown in Figure 6.17 . The web
of plate girder T3 was 914 mm high and 8 mm thick, while the flange of the
plate girder was 229 mmwide and 11-25 mm thick, as shown in Figure 6.17 .
The web was stiffened by steel plates at the end supports and the loading
positions and also stiffened by intermediate stiffeners as shown in
Figure 6.17 . The plate girder was restrained laterally at the end supports
and loading position to resist lateral-torsional buckling. Tensile coupon tests
were conducted to determine the yield and ultimate tensile strength of the
steel used, which were 558 and 621 MPa, respectively. The plate girders
were loaded at midspan using a spreader plate (343 229) as shown in
Figure 6.17 . Strain gauges were used to measure the strains in the plate
girder section, and displacement transducers were used to measure the mid-
span deflections during loading. The strain measurements showed that no
yielding took place and the neutral axis remained stationary until buckling
occurred. The failure mode of the specimen was elastic lateral-torsional
buckling. The ultimate load resisted by the plate girder was 489.3 kN at
a maximum midspan deflection of 40.6 mm. The load-midspan deflection
relationship, load-strain relationships, and the deformed shape at failure
were observed in the test.
To model the full-scale plate girder (T3) tested by Felkel et al. [ 6.8 ] , the
finite element program ABAQUS [1.29] was used. The model has
accounted for the measured geometry, initial geometric imperfections,
and measured material properties of the plate girder. A four-node doubly
curved shell element with reduced integration (S4R) was used to model