PARAM, GYRO1D

Bulk Data Entry Activates/deactivates the calculation of 1D Gyroscopic Matrix for 1D Rotors in Rotor dynamics.

Parameter Values Description
GYRO1D <YES, NO>
YES (Default)
Activates the calculation of 1D Gyroscopic Matrix for 1D Rotors in Rotor dynamics.
NO
Deactivates the calculation of 1D Gyroscopic Matrix for 1D Rotors in Rotor dynamics.

Comments

  1. If the shear stiffness factors K1 and K2 are non-zero, the Timoshenko beam theory is applied to the 1D gyroscopic matrix. Otherwise, Euler beam theory is applied to the 1D gyroscopic matrix. PBARL is always defined as a Timoshenko beam.

    Refer to PBEAM for more details regarding the shear stiffness factors.

  2. OptiStruct will generate an error message, if the following cases occur in presence of PARAM, GYRO1D:
    • If there is a taper in the beam geometry.
    • If offset and pin conditions are used.
    • If the cross-section of the beam is asymmetric.

      The cross-section of the rotor must be symmetric, in which case the area moment of inertias about the neutral axes are equal (I1 = I2) and the shear stiffness factors are equal (K1 = K2).

    • If the neutral axis is offset from the origin (0, 0) of the local coordinate system of the beam.
    • PARAM, GYRO1D is not currently supported with optimization

    The tolerance values for asymmetry and the neutral axis offset can be specified using PARAM, SBTOLRTR.

  3. Non-structural mass is ignored during the analysis in the presence of PARAM, GYRO1D.