A New Atomistic-to-Continuum Thermomechanical Model that Enables a Novel Averaging Method for Molecular Dynamics Simulations

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

The objective of the proposed research is to establish a new atomistic-to-continuum thermomechanical model for describing the relation between atomistic (microscopic) quantities and continuum (macroscopic) quantities in solids. The proposed model allows the development of novel multiscale denoising (averaging) method employed to decompose the dynamical quantities obtained from nonequilibrium molecular dynamics (MD) simulations into their respective local thermal and mechanical contributions. In the proposed research, the thermomechanical model will be established by 1) testing the Gaussian approximation and temperature estimation, 2) developing a multiscale spatial-temporal thresholding estimator, 3) testing the thermomechanical additive model with the new multiscale averaging method, and 4) estimating the continuum stress using the new averaging method. The successful completion of the proposed research will impact a number of disciplines that include mechanics, heat transfer, signal processing, and nonparametric statistics. For example, new multiscale method coupling MD and finite element methods for simulating nonequilibrium thermomechanical processes will be made possible to extend the time and spatial scale of MD simulation. Nanotechnology applications such as laser ablation for nanoscale patterning and laser-assisted imprinting will be benefited tremendously from the proposed research. Efforts to broaden the participation of students including the underrepresented ones include 1) organizing ?nanotechnology visualization? workshops for high schools students in the larger Pittsburgh area, 2) building an interaction platform for high school students in San Francisco, and 3) introducing a new course in computational nanomechanics. These activities will integrate new research results and concepts from this proposal.