Step function

Hello Everyone,

I want to apply a load for a specific time and then remove it. This is the variable that I have defined. To avoid numerical issues I have two questions.
variable oscillate equal -0.001*((-0.5*((exp(20.03(step-50))-1)/(exp(20.03(step-50))+1)))+0.5)

  1. Is there any step function in lammps that I can use instead of using this exp() math function?
  2. How can I use time in PS instead of using step?

Regards,
Hamed

Hello Everyone,

I want to apply a load for a specific time and then remove it. This is the variable that I have defined. To avoid numerical issues I have two questions.
variable oscillate equal -0.001*((-0.5*((exp(20.03(step-50))-1)/(exp(20.03(step-50))+1)))+0.5)

  1. Is there any step function in lammps that I can use instead of using this exp() math function?

you can use any kind of comparison. it will evaluate to 1.0 if true and 0.0 if false.

  1. How can I use time in PS instead of using step?

you have access to all thermo keywords in variable expressions.

axel.