Extruded aluminum decks for pedestrian bridges Design optimization using genetic algorithm
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Structural engineering and building technology (MPSEB), MSc
Publicerad
2023
Författare
FALKENBERG, EMELIE
FREDRIKSSON, MARKUS
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Material efficiency in bridge structures is an important research topic to reduce the
climate footprint and initial costs. One way of increasing material efficiency is to
use appropriate materials where their properties benefit the structure. Aluminium
offers a high stiffness-to-weight ratio, high durability, and is to a large degree re cyclable. These properties make aluminium an interesting material for bridge deck
applications.
The initial cost of the bridge deck has high priority amongst bridge authorities
in Europe. To minimize the initial cost, one target is to minimize material con sumption. This thesis aims to develop an optimization procedure with the objective
to minimize the material consumption of extruded aluminium profiles for pedestrian
bridge deck applications. In the design of the deck, requirements stated in Eurocode
are followed. The optimization is made using a genetic algorithm function from the
global optimization toolbox in the software MATLAB. Cross-sectional geometries
generated by the optimization procedure was evaluated separately by the imple mentation of a FE-module. The FE-module is controlled by parameterized Python
scripting to create a FE-model and execute an analysis in the software ABAQUS
CAE for each iteration.
The optimization provided a cross-sectional geometry for the bridge deck. These
results were used for a cost comparison between the optimized cross-section and
more conventional alternatives in C-Mn and duplex steel. The comparison showed
that the weight per square meter of the resulting optimized profile was significantly
lower compared to the deck alternatives in steel. It also showed that saving from 8%
up to 27% can be made on the initial investment cost if choosing aluminium instead
of a conventional deck alternative in stainless steel. Thus, aluminium is shown to
be a potential alternative to steel.
Beskrivning
Ämne/nyckelord
Optimization, extruded aluminium profiles, pedestrian bridge, bridge deck, genetic algorithm, aluminium bridge, finite element analysis