Bridge geometry - Computational Analysis and Design of Bridge Structures - page 573

18.7 trend of BrIdge comPuter
modelIng and vIsualIzatIon
As a close issue to bridge geometry, bridge computer modeling and visu-
alization have long been the focus of computer technology applications
in bridge engineering. Comparing with applications in other fields, the
advancing of bridge computer modeling and visualization, however, does
not match what modern computer graphics technologies promise and what
bridge engineers expect. Most bridge analysis and design software avail-
able nowadays are still based on mathematics or mechanics model of a
bridge, rather than the engineering model of a true project. What the cur-
rent bridge software provide a typical process of bridge analysis and design
to engineers still is (1) to establish and analyze a bridge's mechanical model,
(2) to check design code for each component based on the analysis results,
and (3) to resize components or adjust structural dimensions and repeat the
previous process if necessary. The benefit of fast technology advancement
in both computer hardware and software improves only the performance of
each step; challenges such as abstracting mechanical model from engineer-
ing model and representing analysis results in the way engineers used to
are still governing the whole process of analysis and design of bridge struc-
tures. Another aspect that shows great potential for advancing in computer
application is visualization. Showing only 2D or 3D frame lines of mechan-
ics model or bridge schematics cannot meet the demanding of bridge analy-
sis and design nowadays.
The modern computer graphics technologies are now well capable of
processing virtual 3D bridge models in great detail. The key to take the
advantage of it is to establish a bridge engineering model, rather than a sim-
plified and abstracted bridge mechanical model. The complexity of bridge
engineering model can be greatly simplified so as to be feasible when a
particular, commonly used bridge type is focused. Figure 18.26 illustrates
some modeling and visualization features as trends envisioned in bridge
analysis, design, and rating applications. Roadway and bridge geometries
are the first part to describe a bridge project. Detailed bridge component
dimensions and materials can be defined further. While a bridge engineer-
ing model is being edited, its true 3D rendering will be reflected in real time
so engineers can get visual feedback instantly. A key feature that makes 3D
rendering more useful, not merely a visual confirmation, is to allow iden-
tification of any component on-the-fly and to bring up its detailed design
parameters for editing. For example, when the highlighted stiffener as
shown in Figure 18.26 is clicked, the stiffener's definition will be showing
up on screen so as to be edited instantly in place. Because the engineering
model is established, the mechanical model can be automatically created
and analyzed. The tedious error-prone process of converting the structural
analysis model and analyzing can be automated. 3D bridge components