Viewing Displacements at a Specified Frequency Step

  1. In the Harmonic study tree, right-click the Results folder and select Define Displacement Plot.
    The Displacement Plot PropertyManager appears.
  2. Under Display do the following:
    1. Set Component to UY: Y Displacement.
    2. Set Units to in.
  3. Set Frequency to 15.69 Hz.
    The step number closest to the operating frequency of 15.69 Hz is shown in .
  4. Click .

    The peak UY displacements at a frequency of 15.69 Hz are shown.

    To compare the results from the harmonic dynamic study with static study results, run the static study and plot the UY displacement. The absolute displacement at the beam mid-span is 1.875e-003 in. The dynamic magnification factor is UY(dynamic) / UY(static) = 0.047 / 0.00188 =25. This value is in agreement with the maximum dynamic magnification value (1/2z=1/2(0.02)=25) since the amplitude of the harmonic load at the second resonant frequency (15.69 Hz) has the maximum load magnitude.

    To avoid the maximum dynamic magnification factor, you can modify the beams such that their resonant frequencies are not in the 12 to 18 Hz range.

Congratulations! You have completed this lesson.