Vibration and damping

Vibration refers to a periodic motion of a structure around a reference point that is caused by an external force or a disturbance. In structural engineering, vibration can be caused by several sources that include wind, earthquakes, or traffic, and it can lead to significant damage.

Damping is a technique used to reduce the amplitude and duration of vibrations, by absorbing or dissipating the energy of the oscillations. There are several ways to achieve damping in structures, including viscous damping, structural damping, and tuned mass damping. The technique of viscous damping involves the use of dampers that contain a fluid or a viscous material, such as oil or silicone. In fact, viscous dampers work by converting the kinetic energy of the vibration into heat energy, which is then dissipated. Structural damping involves modifying the structure itself to improve its damping characteristics, by adding mass or stiffness to the structure in specific locations. Structural damping is typically achieved by adding materials with high damping ratios, such as rubber. Tuned mass damping involves adding a mass or a series of masses to a structure at specific locations to alter its natural frequencies and reduce the amplitude of vibrations. The masses are tuned to the frequency of the vibration, which can effectively cancel out the oscillation. By reducing the amplitude and duration of vibrations, damping can help to improve the safety and reliability of these structures.