Transient stress (modal superposition)

[mechy20]

I am trying to recover stresses for upto 20modes. Transient stress does not seem to have an option for inertia loading. My load is an impact load. When I enter a load curve (f-t)and ask it to recover modes from previous run, it calculates 0 stresses.

I went through all the modes, and it looks like one or more of them was enough to show atleast a small stress.

I am running v20. Perhaps I am using the wrong type of analysis, I also tried frequency response (where I entered g-t data, it still didnt work)

Any suggestions?
Thanks !

 

[GBor]

Can you be a little more precise on what you are trying to do? Generally, I would take this through an event simulation, which has inertial load transfer capabilities, but if you are just trying to determine what happens to a product when one or more frequencies are excited by an impact force, then I'm not sure why you are having trouble.

I haven't done this in a while, but there used to be a checkbox that said "include natural frequencies". You first had to run a modal analysis and then the frequency response.