Reply To: STRESS STRAIN CURVE

[Armin]

Hello,

Assuming that you're using the explicit solver of LS-DYNA, changing the density will alter the critical time step size in your model and that may explain why you have smoother curve when the density is lowered (time step size is lower, please refer to the link below). If you're employing mass-scaling for your simulation, try using the *CONTROL_TIMESTEP card where you can control the time step size using the DT2MS variable.

Time Step in Explicit Dynamics - Lesson 2