How to achieve stress-strain response at low strain-rate (quasi-static uni-axial tensile test )


I am using the LAMMPS (3 Mar 2020). I am trying to get the engineering stress-strain curve for a uniaxial deformation case. I am using “real” unit, with timestep equal to 1. But, due to limited computational resources, I have to apply a very high deformation rate. I have two questions:

  1. How can we relate the stress-strain response output with that of a much lower (real-world) strain rate? (Since my material is rate-sensitive)
  2. Is metadynamics the only way to address this issue or is there an alternative approach?
    Please let me know if you need more information.

I look forward to hearing from you soon. Thank you very much in advance for your time and help.

With best wishes,
Arunjyoti Sinha Roy.

It would be practically impossible to achieve quasi-static strain rate (»0.1/sec) in all-atom or even coarse-grain MD simulation. Simulations would take several months and years.


Huh? In athermal quasistatic deformation simulations, you:

  1. Apply a finite strain increment (e.g. 2.5*10^-4)
  2. Energy-minimize
  3. Goto (1).

They’re faster than low-strain-rate continuous-deformation simulations.