Optimum cost design of controlled cable stayed footbridges

Traditionally, structures and control devices are designed separately. Here an integrated approach is proposed and applied to find the least cost solution of a passive and active cable stayed footbridge. The optimization process reduces simultaneously cost, stress, acceleration and displacement. By using an entropy-based procedure a Pareto solution is obtained by unconstrained scalar function minimization and an efficient polynomial convergence algorithm is employed. The designed controller is compared with an active linear quadratic regulator (LQR). Numerical simulations show that both passive and active optimum designs are efficient, with different geometry, mass distribution and cost (22% higher in the passive design).