We’re putting the final touches on our new badges platform. Badge issuance remains temporarily paused, but all completions are being recorded and will be fulfilled once the platform is live. Thank you for your patience.
General Mechanical

General Mechanical

Topics related to Mechanical Enterprise, Motion, Additive Print and more.

I would like to compare the results of harmonic analysis and transient analysis.

    • KDH
      Subscriber

      First, obtain the FRF by nodal force in the harmonic.

      When I get the FRF in the transient under the same conditions, I want to make sure it is the same as the result in the harmonic.

      But I'm confused about giving the same condition.


      If a nodal force of 10 N is applied in the Y direction in the harmonic, how should it be applied in the transient?


      Finally, how can I compare the two results?

    • peteroznewman
      Subscriber
      I don't understand what you mean in your first two sentences.
      A 10 N force applied in a harmonic response means that a force with an amplitude of 10 N and a sinusoidal waveform was applied to the structure at a range of frequencies. Let's say you specified a lower frequency of 20 Hz and an upper frequency of 200 Hz with a 20 Hz increment. That means the results of the harmonic response was evaluated at 20, 40 60, ... 160, 180 and 200 Hz. That is 10 points on a graph or 10 contour plots.
      To do that in a Transient solution, you need to have 10 transient models. Each one will have a unique input waveform. The first waveform will have a 10 N amplitude with a 20 Hz frequency. The last waveform will have a 10 N amplitude with a 200 Hz frequency.
      You need to simulate each Transient for a long enough time for the transient portion of the solution to decay away leaving only the steady-state solution.
      In the steady-state portion of the solution, you need to find the time when the maximum response is seen since the response will oscillate over time from a maximum value, through zero to a minimum value. It is the maximum response that is captured in the harmonic response analysis.
      I suggest you browse the free courses in the structures category. There are courses on dynamics, modal, harmonic response and transient analysis.
Viewing 1 reply thread
  • The topic ‘I would like to compare the results of harmonic analysis and transient analysis.’ is closed to new replies.