Trying to get minimum load (compression) from direct Frequency Responce

[ANDYPITT1573]

Hello,

I'm trying to do frequency response on a sandwich type arrangement of a crystal trapped between two masses. However whenever I run direct Frequency response, it gives me an arrangement where the crystal is in tension rather than the compression response I'm after.  Is there any way to configure the analysis so that it gives me the response I require?

Thanks!

[John_Holtz]

Hi @ANDYPITT1573 

I have not performed a Direct Frequency Response analysis, so I do not know the answer. What happens if you reverse the direction of the applied load?

In a modal frequency response, the positive and negative result are equal and opposite. Imagine a cantilever beam for example. The results would be equal and opposite for the position with the beam deforming "up" as for the position with the beam deforming "down".

As far as I know, there is no mechanism to control which result is shown. For example, you cannot enter a negative deform option scale factor to make your results look like compression instead of tension. So you may need to ignore the shape and indicate that the results are plus or minus the results shown (if appropriate. The von Mises result is always a positive.)