This option is used to provide global damping factors for the following procedures in Abaqus/Standard:
*STEADY STATE DYNAMICS, DIRECT
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION
Products: Abaqus/Standard Abaqus/CAE
Type: History data
Level: Step
Abaqus/CAE:
Set FIELD=ACOUSTIC to apply the global damping only to the acoustic fields in the model.
Set FIELD=ALL (default) to apply the global damping to all of the valid displacement, rotation, and acoustic fields in the model.
Set FIELD=MECHANICAL to apply the global damping only to the valid displacement and rotation fields in the model.
Set this parameter equal to the 
factor to create global Rayleigh mass proportional damping 
, where 
denotes the model mass matrix. The default is ALPHA=0. (Units of T–1.)
Set this parameter equal to the 
factor to create global Rayleigh stiffness proportional damping 
, where 
denotes the model stiffness matrix. The default is BETA=0. (Units of T.)
Set this parameter equal to the 
factor to create frequency-independent stiffness proportional structural damping 
, where 
denotes the model stiffness matrix. The default is STRUCTURAL=0.