Creating Base Motion Boundary Conditions

Base motion boundary conditions specify the motion of nodes in a steady-state dynamic (mode-based or subspace-based) step. The base motion can be acceleration, velocity, or displacement.

This task shows you how to create a base motion boundary condition in a steady-state dynamic step.

  1. With a (mode- or subspace-based) steady-state dynamic step selected, click the Base Motion Boundary Condition icon .

    The Base Motion BC dialog box appears, and a Base Motion object appears in the specification tree under the Boundary Conditions objects set for the current step.

  2. You can change the identifier of the boundary condition by editing the Name field.

  3. If you want to apply the base motion to a secondary base, toggle on Use secondary base motion and select a clamp or displacement boundary condition defined in the previous Frequency step as the support you want to use as the secondary base boundary condition. If you want to apply the base motion to the primary base, leave the Support field blank.

  4. Specify the magnitude/phase data or real/imaginary data for this boundary condition:

    1. Toggle on Use magnitude-phase data to specify data in terms of magnitude and phase, or toggle off this option to specify data in terms of real and imaginary components.

    2. Enter or import the data you want to specify to describe the motion of nodes for this base motion boundary condition.

  5. From the DOF options, specify the direction for which the base motion is being defined. Abaqus for CATIA V5 filters the list of selectable degrees of freedom down to the list of degrees of freedom specified for the selected support.

  6. If desired, specify a scale factor for the amplitude curve in the Scale field. The default value is 1.0.

  7. From the Base motion type options, select Acceleration, Velocity, or Displacement.

  8. For primary base motion, specify the Center of rotation.

  9. Click OK in the Base Motion BC dialog box.

    If you specified base motion for a secondary base, symbols representing the degrees of freedom driven by the base motion boundary condition are displayed. Abaqus for CATIA V5 does not display symbols if you apply the base motion to the primary base.