PARAM, WR4

Bulk Data Entry Used to include or exclude rotor material damping in rotor dynamics analysis.

Parameter Values Description
WR4 <Real>

Default = 0.0

PARAM, WR4, <Real>

For Complex Eigenvalue or Transient Analysis:

If any Real value other than 0.0 (default) is specified, then it is included in the rotor dynamics equation as the equivalent “average” excitation frequency. This allows for the inclusion of the material damping terms in the analysis.

For Frequency Response Rotor Dynamics Analysis:

When PARAM, GYROAVG is set to -1 (in order to bypass frequency dependent looping), only if any real value other than 0.0 (default) is specified for WRH, then it is included in the rotor dynamics equation via the material damping term as the equivalent “average” excitation frequency. When PARAM, GYROAVG is not -1, this parameter is irrelevant.

Refer to Rotor Dynamics in the User Guide for more details.

Comments

  1. This parameter can be specified in the Bulk Data section and/or Subcase section. If it is defined in the Subcase section, then it is subcase-specific and this value is only used for this subcase.
  2. PARAM, WR4 is supported with complex eigenvalue, modal frequency response and transient solution sequences for rotor dynamics.
  3. The order of priority is TSTEP or RSPINR/RSPINT entry, Subcase specific PARAM, followed by Bulk Data PARAM.