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(2*0.03*(step-50))-1)/(exp(2*0.03*(step-50))+1)))+0.5)

- Is there any step function in lammps that I can use instead of using this exp() math function?
- 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(2*0.03*(step-50))-1)/(exp(2*0.03*(step-50))+1)))+0.5)

- 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.

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

you have access to all thermo keywords in variable expressions.

axel.