Failure using a Harmonic Analysis

[jamesbewley]

Hello

I am running a harmonic response analysis in Workbench V11.

I am struggling to understand how to interprate the results to show if the component is "failing" or not.

Does anyone have any advice on the best way to approach this.

I am thinking that the results should somehow be assesed against an S-N curve and cumulative damage taken into account.

Many thanks in advance for your help.


James

 

[cbrn]

Hi,
as a rule of thumb, no analysis (be it FEA or hand-calc) should be made witohout knowing why you are performing it.

The harmonic response does what it is called for: it calculates the vibratory response of a structure subjected to an exciting source (sine imposed displacement, sine force, sine acceleration,...).

With that, you calculate response curves, i.e. the curve of vibration amplitude vs. exciting frequency, for any location (say node, in FEM) of interest. You can perform vibration evaluations (e.g.: "is the peak-to-peak displacement amplitude at the centerline of the bearing compatible with the specification's limit?"), and see if you cross resonances (so that you can see which are the ranges of excitation frequencies which are to be avoided, or vice-versa if you know the possible exciting frequencies which the structure undergoes during service, you can check if they fall in the "prohibited ranges" or not).

Regards