Viscous damping is a convenient analytical concept to account for general
energy dissipation and analytical uncertainties. Viscous damping is usually
used to represent the following:
 Friction
between and with structural and nonstructural elements
 Localized
yielding due to stress concentrations and residual stresses under low
loading and gross yielding under higher loads
 Energy
radiation through foundation
 Aeroelastic
damping

Viscous damping

Analytical modeling errors
Viscous
Damping Values for Design
Many
codes stipulate 5% viscous damping unless a more properly substantiated
value can be used. Note that actual damping values for many systems, even
at higher levels of excitation are less than 5%.
