Defining Harmonic Loading

You apply the out-of-balance force of 60 lb produced by the AC unit rotating at frequency range 12 to 18 Hz. The force is applied to 4 faces with each face carrying 15 lbs.

1. In the FeatureManager Design Tree, right-click the ac_box part, and click Hide components.
2. In the Harmonic study tree, right-click External Loads and click Force .
3. In the graphics area, select the four faces shown in the figure.
   

   The four faces appear in the Faces and Shell Edges for Normal Force box.

4. Set Unit to English (IPS).
5. For Force Value , enter 15 lbf.
   Check that Per item is selected.
6. Under Variation with Frequency, select Curve and click Edit.
7. Set Units to Hz.
8. Enter the following values for the force curve data:

   Points	X	Y
   1	10	0
   2	12	1
   3	18	1
   4	20	0

   The frequency range of the force values must be covered by the frequency range specified in the properties of the harmonic study.
9. Click OK.
10. Click .
    Show the hidden ac_box part.