SRSS

SRSS, SIGNIF, Label, AbsSumKey, ForceType
Specifies the square root of sum of squares mode combination method.

Valid Products: Pro | Premium | Enterprise | PrepPost | Solver | AS add-on

SIGNIF

Combine only those modes whose significance level exceeds the SIGNIF threshold. For single-point, multi-point, or DDAM response spectrum (Spectype = SPRS, MPRS, or DDAM on SPOPT), the significance level of a mode is defined as the mode coefficient divided by the maximum mode coefficient of all modes. Any mode whose significance level is less than SIGNIF is considered insignificant and is not contributed to the mode combinations. The higher the SIGNIF threshold, the fewer the number of modes combined. SIGNIF defaults to 0.001. If SIGNIF is specified as 0.0, it is taken as 0.0. (This mode combination method is not valid for SPOPT,PSD.)

Label

Label identifying the combined mode solution output.

DISP

 — 

Displacement solution (default). Displacements, stresses, forces, etc., are available.

VELO

 — 

Velocity solution. Velocities, "stress velocities," "force velocities," etc., are available.

ACEL

 — 

Acceleration solution. Accelerations, "stress accelerations," "force accelerations," etc., are available.

AbsSumKey

Absolute Sum combination key (for SPOPT,MPRS only):

NO

 — 

Do not use the Absolute Sum method (default).

YES

 — 

Combine the modes per excitation direction using the Absolute Sum method, then combine the resulting quantities using the square root of sum of squares method.

When using Absolute Sum combination, the excitation direction must be specified using the SED command.

ForceType

Label identifying the forces to be combined:

STATIC

 — 

Combine the modal static forces (default).

TOTAL

 — 

Combine the modal static plus inertial forces.

Notes

This command is also valid for PREP7.

Menu Paths

Main Menu>Preprocessor>Loads>Load Step Opts>Spectrum>Mode Combine>SRSS Method
Main Menu>Preprocessor>Loads>Load Step Opts>Spectrum>MultiPt>Mode Combine>SRSS Method
Main Menu>Preprocessor>Loads>Load Step Opts>Spectrum>SinglePt>Mode Combine>SRSS Method
Main Menu>Solution>Load Step Opts>Spectrum>Mode Combine>SRSS Method
Main Menu>Solution>Load Step Opts>Spectrum>MultiPt>Mode Combine>SRSS Method
Main Menu>Solution>Load Step Opts>Spectrum>SinglePt>Mode Combine>SRSS Method