Bulk Data Entry Defines the cut-off eigenvalue for determining rigid body modes calculated by AMLS.

Parameter Values Description

Default = 1.0


The default cutoff eigenvalue (AMSES and AMLS) is 1.0, if this parameter is not present in the deck.

PARAM, RBMEIG defines the cutoff eigenvalue for determination of rigid body modes calculated by the AMLS and AMSES eigensolvers.


  1. PARAM, RBMEIG functions in a similar manner to PARAM, FZERO, which is used in models solved by the Lanczos eigensolver.
  2. The default cutoff eigenvalue of 1.0 is equivalent to a natural frequency of 0.16 Hz.
  3. For the Lanczos eigensolver, use PARAM, FZERO to set the cutoff frequency for rigid body modes.