October 24, 2023 at 11:30 am
Erik Kostson
Ansys Employee

 

 

 

 

 

Hi

So you need to have at least 10 time steps in one period to capture a free vibration. Ideally 20 steps per period.

So say the free vibration of interest is 10Hz, or T_period=0.1 s, then the time step in the analysis settings should be T/10 = 0.01 s at least or even better T/20 = 0.005 s (at least for the 2nd step when the free vibration occurs).

See here for more info (3 min.30 s mark – 6 minute mark in the below – time step discussion):

https://www.youtube.com/watch?v=DnfGaJgbXcw

 

All the best

Erik