Learning Forum

[Killian HOLLEBEKE]

Hi everybody.

I'm a new user of Ansys LS-DYNA workbench and can't see where I can specify the time step that I want to impose in my model.

Thanks in advance.

[Ram Gopisetti]

Hi Killian, 

A bit of background on the time step :

When employing explicit dynamics, the timestep is determined by the solver, considering factors such as the smallest element size, material properties (E and rho), and the TSSFAC parameter (default=0.9) in *CONTROL_TIMESTEP. The explicit timestep adheres to the CFL stability criteria.

In explicit dynamics, you have the option to define an initial timestep using *CONTROL_TIMESTEP (typically set by the solver) and can constrain the maximum timestep using a load curve (*DEFINE_CURVE) with the LCTM parameter.

Now, you cannot set the DTINIT in workbench ls-dyna, directly but you can use keyword manager or the command snippet method as described in /forum/forums/topic/defining-and-using-cyl-cs-in-wb-dyna/  fourth thread, however, you can use the Time step control option which will define the LCTM as a curve at the back (.k file)

Cheers, Ram