1
Abstract
In the last decades there is an increasing interest and investigation in the area of
control applied to civil engineering structures. It’s been shown that it is possible to
improve structural performance by providing control devices that use sensors
information to modify the dynamic properties.
An integrated cable-stayed bridge and control strategy system is designed in view of
improving safety against dynamic loading, in particular pedestrian vibration.
The design problem concerns the optimization with goals of minimum cost, stresses,
accelerations and displacements. It is cast as a multi-objective optimization and a
Pareto solution is sought. An entropy-based technique is used to find the minimax
solution by minimizing a convex scalar function.
Keywords: cable stayed, structural control, multi-objective optimization, integrated
design.
1 Introduction
Traditionally, structures and their control devices are designed separately. An
integrated optimum design is proposed here for a cable stayed pedestrian bridge.
Tzan and Pantelides [1] presented a methodology to optimally design an active
frame subject to seismic excitation, the objective being minimize the structural
volume with constraints of story drift and stresses. Khot [2] proposed an approach to
optimally design integrated space systems using multi-objective optimization with
goals of minimum volume, control force and time to suppress oscillations. In 2008
Cimellaro et al. [3] illustrated a two-stage optimization procedure for designing
active steel frames. In 2009 Cimellaro et al. [4] extended their work to account for
inelastic structures.
Steel footbridges are usually very flexible structures this, added to their low inherent
damping, amplifies their response under dynamic loading. SETRA [5] published a
Paper 167
Optimum Design of Active and
Passive Cable Stayed Footbridges
F.L.S. Ferreira
1
and L.M.C. Simoes
2
1
Department of Civil Engineering
University of Oporto, Portugal
2
Department of Civil Engineering
University of Coimbra, Portugal
©Civil-Comp Press, 2010
Proceedings of the Tenth International Conference
on Computational Structures Technology,
B.H.V. Topping, J.M. Adam, F.J. Pallarés,
R. Bru and M.L. Romero, (Editors),
Civil-Comp Press, Stirlingshire, Scotland