Windresonant

Windresonant is a term used in wind engineering to describe a resonance condition that occurs when atmospheric wind loading excites the natural vibration modes of a structure or flow system, producing sustained oscillations with greater amplitudes at certain wind speeds. The concept lies within aeroelasticity and is related to, but distinct from, flutter and vortex-induced vibration.

The primary mechanisms involve aerodynamic excitation at frequencies near a structure’s natural modes, lock-in or synchronization between vortex shedding and structural oscillation, and buffeting from turbulent winds. When the excitation frequency aligns with a structural natural frequency, even moderate wind can yield large responses, particularly for slender or flexible elements.

In engineering practice, windresonant concerns arise for tall towers, chimneys, bridges, masts, and wind turbine components, where resonance can lead to material fatigue or serviceability issues. It is also discussed in studies of urban buildings subjected to gusty wind flows and complex wind environments.

Assessment relies on wind tunnel testing, field monitoring, and aeroelastic simulations to identify resonant wind speeds and modes. Mitigation options include tuning natural frequencies away from dominant wind excitation, increasing damping, using tuned mass dampers, aerodynamic shaping, and structural stiffening.

See also: wind engineering, aeroelasticity, vortex-induced vibration, resonance.