PSDUNIT
PSDUNIT, TBLNO, Type, GVALUE
Defines the type of input PSD.
- TBLNO
- Input table number. 
- Type
- Label identifying the type of spectrum: - DISP - — - Displacement spectrum (in terms of displacement2/Hz ). - VELO - — - Velocity spectrum (in terms of velocity2/Hz ). - ACEL - — - Acceleration spectrum (in terms of acceleration2/Hz ). - ACCG - — - Acceleration spectrum (in terms of g2/Hz ). - FORC - — - Force spectrum (in terms of force2/Hz ). - PRES - — - Pressure spectrum (in terms of pressure2/Hz ). 
- GVALUE
- Value of acceleration due to gravity in any arbitrary units for Type=ACCG. Default is 386.4 in/sec2. 
Notes
Defines the type of PSD defined by the PSDVAL, COVAL, and QDVAL commands.
Force (FORC) and pressure (PRES) type spectra can be used only as a nodal excitation.
GVALUE is valid only when type ACCG
is specified.  A zero or negative value cannot be used.  A parameter
substitution can also be performed.
This command is also valid in PREP7.