MDStressLab – Computing Stress Fields in Atomistic Simulations

[Stress decomposition Image]
Decomposition of the atomistic stress in the yy-direction (vertical) for a plate containing a hole in tension generated by MDStressLab. The total stress field shown on the left is decomposed into a unique irrotational part and a non-unique traction-free solenoidal part that depends on the interatomic potential extension. Source: N. C. Admal and E. B. Tadmor (2016b).

Overview

MDStressLab is a KIM-compliant program (see https://openkim.org) for postprocessing molecular dynamics or molecular statics results to obtain stress fields using different definitions of the atomistic stress tensor.

MDStressLab has the following capabilities/features:

  1. Calculate fields of the Cauchy and first Piola-Kirchhoff versions of the Hardy, Tsai and virial stress tensor on a user-specified grid. See Admal and Tadmor (2010 and 2011) and Admal and Tadmor (2016a).
  2. Decompose any of the atomistic stress tensors into a unique irrotational part and a non-unique solenoidal part as studied in Admal and Tadmor (2016b).

For more information, see the User Manual (click on menu item on left).

Authors

The code was written by Dr. Nikhil Chandra Admal (UCLA), Min Shi (U. Minnesota) and Prof. Ellad B. Tadmor (U. Minnesota) and is based on their joint research (see below).

How to cite MDStressLab

When publishing results obtained using this program, please indicate that the code was obtained at http://mdstresslab.org and cite the relevant publications from the following list on which it is based:

  1. N. C. Admal and E. B. Tadmor, 2010. A unified interpretation of stress in molecular systems. Journal of Elasticity 100, 63–143.
  2. N. C. Admal and E. B. Tadmor, 2011. Stress and heat flux for arbitrary multi-body potentials: A unified framework. Journal of Chemical Physics 134, 184106.
  3. N. C. Admal and E. B. Tadmor, 2016a. Material fields in atomistics as pull-backs of spatial distributions. Journal of the Mechanics and Physics of Solids, 89, 59–76.
  4. N. C. Admal and E. B. Tadmor, 2016b. The non-uniqueness of the atomistic stress tensor and its relationship to the generalized Beltrami representation. Journal of the Mechanics and Physics of Solids, 2016, 93, 72–92.