Modal Damping
Modal damping is defined as a ratio of
the critical damping Ccr
for each mode. Critical damping Ccr
is the least amount of damping that causes a system to return to its equilibrium
position without oscillating.
The modal damping ratio can be determined accurately with proper field
tests. The ratio varies from 0.01 for lightly damped systems to 0.15 or
more for highly damped systems.
When experimental data is not available, use data from a similar class
of systems to determine the damping properties. Smaller ratios are more
conservative since higher ratios reduce vibration amplitudes. In general,
neglecting damping leads to a conservative estimate of the system's response.
Click here for a list of damping ratios
for different systems.
Related topics
Global
Damping