Abstract
The molecular rearrangements of most fluids under flow and deformation do not directly follow the macroscopic strain field. In this work, we describe a phenomenological method for characterizing such nonaffine deformation via the anisotropic pair distribution function (PDF). We demonstrate how the microscopic strain can be calculated in both simple shear and uniaxial extension, by perturbation expansion of anisotropic PDF in terms of real spherical harmonics. Our results, given in the real as well as the reciprocal space, can be applied in spectrum analysis of small-angle scattering experiments and nonequilibrium molecular dynamics simulations of soft matter under flow.
| Original language | English |
|---|---|
| Article number | 012605 |
| Journal | Physical Review E - Statistical, Nonlinear, and Soft Matter Physics |
| Volume | 97 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 10 2018 |
Funding
This work was sponsored by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. This research at the Spallation Neutron Source and the Center for Nanophase Materials Sciences of Oak Ridge National Laboratory was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. The computational work in this study used the resources of the Oak Ridge Institutional Clusters. Y.Y.W. acknowledges support by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the US Department of Energy. G.-R.H. acknowledges support from the National Center for Theoretical Sciences, Ministry of Science and Technology, in Taiwan (Project No. MOST 106-2119-M-007-019) and the Shull Wollan Center during his visit to Oak Ridge National Laboratory. We thank Peter Schall and Alessio Zaccone for helpful discussions.
| Funders | Funder number |
|---|---|
| Center for Nanophase Materials Sciences of | |
| Scientific User Facilities Division | |
| US Department of Energy | |
| Battelle | |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Laboratory Directed Research and Development | |
| National Center for Theoretical Sciences | |
| Ministry of Science and Technology, Taiwan |