Structures vibration have different origins
- wind and vortex
- earthquake
- walking of pedestrians on a bridge or footbridge
- machine excitation..
Wind exited structure
At a given wind speed vortex are generating around the structure. When the critical wind speed is obtained the structure is a subject to resonance phenomenon. The intensity of the phenomenon is bigger when the structures damping is small.
Case of circular section




Case of a bdridge beam

