Reply To: Behavior of a structure experiencing a shock

[Erik Kostson]

No worries happy to help .

In your case except of the time step that should be one tenth of that smallest period of interest. So the smallest period is(1/30Hz) ~ 0.033s, and thus the time step is equal to 0.003 s we also need to have a time step that captures your shock, and again we should have a a time step that is say one tenth of the shock period.
In your case the pulse period seems to be about 0.08 s, so 0.003 s is more than enough to capture that schock.
Finally you seem to run the full transient (not mode superposition), so we use the implicit scheme. Have in mind though that if you have nonlinearities since the we need the NewtonRap. iterations for everytime tep, and we might then need a smaller time step than 0.003 to get convergence (so perhaps have substeps maximum say to 10 - or define the minimum time step say as a start one tenth of the main time step of 0.003 s, so for the minimum 0.0003s.
All the best

Erik