The amplitude of these oscillations is time dependent and is inversely proportional to the time. Higher damping means that the oscillations reduce in their size (Fang et al. 1999).
In physics’ terms, the tendency of a system to oscillate at amplitude that is greater at certain frequencies as compared to others is called resonance. This situation occurs when the system has the capacity to stockpile and shift energy easily between more than two modes of storage. The losses that happen at the process of this cycle are called damping. With small damping, the resonance frequency tends to be the same as the natural frequency of the system. There are cases where systems have multiple resonance frequencies that are distinct (Kijewski-Correa and Pirnia, 2007).
Damping is hence the physical phenomenon of reducing motion through dissipation of energy. In tall buildings, damping is important due to various reasons. The tall buildings are known to vibrate at natural frequencies that are low. This is a factor that makes the buildings to be very susceptible to dynamic resonance in cases of earthquake and wind. Wind energy is usually at its highest when the frequencies are low. Additionally, to the response to the wind gustiness, there is a common form of dynamic wind response that is due to vortex shedding. The circumstances mentioned results to the creation of movements of the structure that is at right angles to the course of the storm (Terman, 1992).
Damping in tall buildings is mainly caused by intrinsic and supplementary sources. Intrinsic damping comes from connections, cladding, friction and seismic motion; in this case, this paper is interested in the seismic causes of the damping which is earthquakes. Supplementary damping is due to engineered devices such as friction devices, viscous and slosh dampers and tuned mass dampers (Katsuhiko, 2005). There are broad methods that have been largely