SPUNIT

SPUNIT, TBLNO, Type, GVALUE, KeyInterp
Defines the type of multi-point response spectrum.

TBLNO

Input table number.

Type

Label identifying the type of spectrum:

DISP	—	Displacement spectrum (SPVAL values interpreted as displacements with units of length).
VELO	—	Velocity spectrum (SPVAL values interpreted as velocities with units of length/time).
ACEL	—	Acceleration spectrum (SPVAL values interpreted as accelerations with units of length/time²).
ACCG	—	Acceleration spectrum (SPVAL values interpreted as accelerations with units of g/time²).
FORC	—	Force spectrum.
PRES	—	Pressure spectrum.

GVALUE

Value of acceleration due to gravity in any arbitrary units for Type=ACCG table. Default is 386.4 in/sec².

KeyInterp

Key to activate or deactivate the linear interpolation between input response spectrum points and input response spectrum curves:

0 (OFF or NO)	—	Deactivate linear and use logarithmic interpolation. This value is the default.
1 (ON or YES)	—	Activate linear interpolation.

Command Default

Acceleration (ACEL) spectrum (length/time²).

Defines the type of multi-point response spectrum defined by the SPFREQ and SPVAL 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.

Main Menu>Preprocessor>Loads>Load Step Opts>Spectrum>MultiPt>Settings

Main Menu>Solution>Load Step Opts>Spectrum>MultiPt>Settings