# Modal Damping dialog

Used to define unique damping ratios for the individual modes used in a dynamic analysis. It is used in response spectrum and time history analysis.

Opens when the
Modal Damping
tool is selected in the
Dynamic Specifications group on the
Loading ribbon tab.

Note: STAAD.Pro is also
capable of calculating each mode's damping based on the frequency of the mode,
the mass-proportional damping coefficient (α), and the stiffness-proportional
damping coefficient (β). This input must be provided using the
STAAD.Pro Editor. Refer to
Calculate Damping
for additional details.

Setting | Description |
---|---|

Evaluate | This option is to instruct
STAAD.Pro to calculate the damping
ratio for each mode based on the frequency of the mode and the
Minimum and
Maximum values entered in the respective
fields.
The formula used to evaluate the damping ratio is explained in Evaluate Damping. |

Explicit | Provide values of damping ratio for the
corresponding mode number.
Refer to Explicit Damping for additional details. |