TABDMP2
Bulk Data Entry Defines modal damping as a tabular function of mode index.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

TABDMP2  TID  TYPE  
$m{s}_{1}$  $m{e}_{1}$  ${g}_{1}$  
$m{s}_{2}$  $m{e}_{2}$  ${g}_{2}$  
etc.  etc.  etc. 
Example
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

TABDMP2  1001  
1  0.010  
2  8  0.124  ENDT 
Definition
Field  Contents  SI Unit Example 

TID  Table identification number. No default (Integer > 0) 

TYPE  Damping units type. 7


$m{s}_{i}$  Index of the lowest mode of a range. No default (Integer ≥ 1) 

$m{e}_{i}$  Index of the highest mode of a range. 5
(Integer ≥ $m{s}_{i}$ ) 

${g}_{i}$  Fraction of critical damping. No default (Real > 0.0) 
Comments
 Modal damping tables must be selected in the Subcase Information section, using the SDAMPING entry. This form of damping is supported in Modal Transient, Modal Frequency Response Analysis, Modal Complex Eigenvalue Analysis and Response Spectrum Analysis.
 A METHOD statement must be present in the SUBCASE.
 At least one continuation entry must be specified.
 The end of the table is indicated by the existence of ENDT in either of the two fields following the last entry. An error is detected if any continuations follow the entry containing the endoftable flag ENDT.
 When the $m{e}_{i}$ field is left blank, it is assumed to be the same as and the damping is applied only to a single mode.
 The KDAMP option, on the
PARAM card, may be used to switch between viscous and
structural damping. Viscous is the default and is used when PARAM, KDAMP is not present.
 KDAMP
 Results
 1 (Default)
 B matrix
 1
 $\left(1+ig\right)K$ matrix
 If TYPE is
G or blank, the damping values
${g}_{i}$
are in units of equivalent viscous damping
as:
(1) $${b}_{i}=\frac{{g}_{i}}{{\omega}_{i}}{k}_{i}$$If TYPE is CRIT, the damping values ${g}_{i}$ are in units of fraction of critical damping $C/{C}_{0}$ .
If TYPE is Q, the damping values ${g}_{i}$ are in the units of amplification or quality factor, Q. These constants are related by the following equations:(2) $$\frac{C}{{C}_{0}}=\frac{g}{2}$$(3) $$Q=\{\begin{array}{c}\frac{1}{\left(\frac{2C}{{C}_{0}}\right)}\\ \frac{1}{g}\end{array}$$  To achieve identical displacements in Modal frequency
response or Modal transient analyses when the SDAMPING is
used instead of PARAM, G, the steps
described here can be followed:
 The TYPE field in the TABDMP1 or TABDMP2 Bulk Data Entry should be set to CRIT. This TABDMP1 Bulk Data Entry is referenced by the SDAMPING Subcase Information Entry.
 Set the damping value (field ${g}_{i}$ ) in the TABDMP1 or TABDMP2 Bulk Data Entry equal to half of the value of PARAM, G (set to the constant value to $C/{C}_{0}$ ).
 Set PARAM, KDAMP,1