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

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1

Hello,

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.

2

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.

Sanjib

3

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.

Best,
Rob