A reliability study for the Messina Bridge with respect to flutter phenomena considering uncertainties in experimental and numerical data

• Reliability was obtained using each point of flutter derivatives as random variable.
• A modified FORM was proposed to avoid numerical instability in reliability index.
• Two very different structural typologies were studied with this approach.
• The most influential flutter derivatives on reliability analysis are A2 and A3.
• Depending on typology, the same data dispersion influences differently on safety.

The First-Order Reliability Method is applied to bridge flutter instability considering uncertainties in structural damping, flutter derivatives and extreme wind velocity. The baseline is to set each flutter derivative value as a random variable for computing the failure probability by flutter. The flutter speed is obtained by solving the dynamic equilibrium equation. Hence performance function cannot be expressed explicitly. Reliability sampling methods are not considered in this paper because it would require a large computational time. A modification of Hasofer-Lind–Rackwitz-Fiessler algorithm is proposed for avoiding numerical oscillations. Finally, the methodology proposed is applied to the Messina bridge project.