ROSE

ROSE, SIGNIF, Label, TD, ForceType
Specifies the Rosenblueth mode combination method.

SOLUTION: Spectrum Options

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 does not contribute 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.

TD

Time duration for earthquake or shock spectrum. TD defaults to 10.

ForceType

Label identifying the forces to be combined:

STATIC	—	Combine the modal static forces (default).
TOTAL	—	Combine the modal static plus inertial forces.

Notes

For more information on spectrum analysis combination methods, see Combination of Modes.

Modes whose effective damping ratio defined in Equation 14–42 exceeds or equals 1.0 are not combined.

This command is also valid in PREP7.

Menu Paths

This command cannot be accessed from a menu.