Analysis of Local Strain Distributions from Two-Point Spatial Correlation Functions

Guan-Rong Huang^1,2*, Bin Wu³, Yangyang Wang⁴, Wei-Ren Chen³

¹Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
²Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
³Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
⁴Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

* Presenter:Guan-Rong Huang, email:d01222004@cts.nthu.edu.tw

The molecular rearrangements of most soft matter flow and deformation do not directly follow the macroscopic strain field. This work describes an analytic approach 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 through 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 flow and deformation.

Keywords: Soft Matter Flow and Deformation, Local Strain Distribution, Pair Distribution Function, Small-Angle Scattering Experiments, Non-equilibrium Molecular Dynamics Simulations