Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 27

life assessment of steel bridges using structural health monitoring data. The
authors applied the proposed method to assess the fatigue status of critical
welded details on the instrumented Tsing Ma Bridge carrying both highway
and railway traffic. It was shown that the proposed method makes it conve-
nient to simultaneously consider the effects of different loads (highway traf-
fic, railway traffic, monsoon, and typhoon) with the use of a single standard
stress spectrum. It was shown that, in applying the proposed method, it was
unnecessary to separate the temperature-induced ingredient and slow-
varying drift from the raw measurement data. The authors concluded that
a standard daily stress spectrum accounting for highway traffic, railway traf-
fic, and typhoon effects can be formulated from the long-term monitoring
data by combining the standard traffic-stress spectrum and standard
typhoon-stress spectrum proportionally. It was also concluded that, for
the Tsing Ma Bridge, the predicted fatigue life was varying slightly when
using more than 10 daily strain data and keeps almost the same when using
more than 20 daily strain data. In addition, it was concluded that the pro-
posed method provided a feasible approach for fatigue life assessment of
welded details on steel bridges by using field monitoring data from a struc-
tural health monitoring system. Investigating the mechanical properties of
new materials used in steel bridges is also a current research area. Mo
et al. [ 1.49 ] investigated the mechanical properties of thin epoxy polymer
overlay materials upon steel bridge decks. Overall, the authors highlighted
the epoxy binder-steel bonding behavior, dynamic response of epoxy
binder, and response and fatigue behavior of epoxy polymer concrete.
The test data obtained indicated that epoxy binder-steel bonding exhibited
a strong temperature dependency. Also, fatigue models on epoxy binder-
steel bonding and epoxy polymer concrete were developed using the
power-law equation. It was shown that response models for epoxy binder
and their concrete can be properly established. The developed material
response models can be served for finite element simulations on thin epoxy
polymer concrete overlay upon steel bridge decks.
Proposing approximate methods for estimating collapse loads of steel
bridges with complex geometry is a current research area. Although non-
linear inelastic analysis is commonly used to determine the collapse loads
of these bridges and accounts for all geometric and material nonlinear aspects
of the bridge system, approximate methods can be useful in the preliminary
design stages. Yoo et al. [ 1.50 ] proposed a simple alternative for complex
nonlinear inelastic analysis to estimate the collapse load of a steel cable-stayed
bridge. The fundamental theories of nonlinear inelastic analysis and inelastic