Reply To: MODAL ANALYSIS

[dave]

Hi Antony, to clarify I mean run the analysis with the pipe in contact and again without contact, that way you will know the two possible natural frequencies of the system.  I assume the freqencies are needed to check for resonance.  This will likely be the quickest way.

If you want to do a dynamic analysis, you will need to vibrate the model and review the behaviour.  For e.g. seismic applications, the input frequency-displacement or acceleration spectra are known and applied at the supports and the response of the model is reviewed.  An explicit dynamic analysis can take a long time to run since it needs lots of small timesteps.  The results may also be affected by the direction of the input spectra, so various input spectra may need to be run.  A large displacement implicit analysis may be quicker, but can still take a long time to analyse.  It can be a lot of work and take a lot of postprocessing, hence I would stick with the linear option if possible.