SRS (Structural Response Spectrum)

Description

The SRS entry defines a set of grid point locations for which a structural response spectrum will be computed for the dynamic event.

Format

1	2	3	4	5	6	7	8	9	10
SRS	SID	NSID	MINFREQ	MAXFREQ	NUMINC	FILTERF	GRAV

Example

SRS	5	99	100.	8000.	1000.	1000.	386.4
	1.	2.	3.	4.	5.

Field	Definition	Type	Default
SID	Identification number.	Integer > 0	Required See Remark 1
NSID	Set identification number.	Integer > 0	Required See Remark 2
MINFREQ	Minimum frequency (Hertz) for structural response spectrum.	Real	1.
MAXFREQ	Maximum frequency (Hertz) for structural response spectrum.	Real	200.
NUMINC	Number of frequence increments in structural response spectrum.	Integer > 0	100
FILTERF	Filter frequency (Hertz).	Real ≥ 0	1.
DFi	Damping fractions (percent of critical damping)	Real	See Remark 4

Remarks

1. SID must reference a DLOAD ID in the Case Definition.
2. NSID must reference a valid set of GRID IDs defined in the Case Definition.
3. If the FILTERF value is zero the acceleration history is not filtered prior to computing the structural response spectrum.
4. Enter as many damping factors as desired. The case for zero damping is automatically included so the line containing damping factors can simply be skipped if desired.