Seminar is in ARMS 1028 From: Son, Rosemary E Sent: Friday, December 08, 2017 1:47 PM To: 'msefaculty-list@ecn.purdue.edu' <msefaculty-list@ecn.purdue.edu>; 'msegradstudent-list@ecn.purdue.edu' <msegradstudent-list@ecn.purdue.edu>; 'msepostdoc-list@ecn.purdue.edu' <msepostdoc-list@ecn.purdue.edu> Cc: 'Michael N Sakano' <msakano@purdue.edu>; Koslowski, Marisol <marisol@purdue.edu>; Son, Steven F <sson@purdue.edu>; Cline, Vicki L. <vicline@purdue.edu>; Son, Rosemary E <son39@purdue.edu> Subject: Seminar Notice for Michael Sakano's Preliminary Exam: Seminar, Friday, Dec. 15, at 9:00 a.m., in ARMS 1028; Exam, same day, at 1:30, in ARMS 2222. "Upscaling Molecular Dynamics Simulations for the Decomposition of High Energy Materials" Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Upscaling Molecular Dynamics Simulations for the Decomposition of High Energy Materials" By Michael N. Sakano Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Alejandro Strachan ABSTRACT Typical molecular dynamics (MD) simulations for describing the chemical reactivity of high energy materials can only achieve up to a couple nanoseconds of data for systems on the order of a few hundred nanometers, due to their computational intensity. One solution is to implement the MD results as inputs into larger-scale models to allow for exploring chemical kinetics in sizable systems and for longer times. Two methods of interest are coarse-graining through Dissipative Particle Dynamics with constant Energy (DPDE) and continuum mechanics modeling using Gibbs formulation, both of which provide reactivities that closely mirror all-atom simulations. These methods are favored in terms of studying the behavior of high energy materials at experimental temperatures, where reactions take tens of microseconds to occur. This work reviews the DPDE and Gibbs formulation methods as a basis for modeling the chemical decomposition of nitromethane and RDX. Background for reactive molecular dynamics (RMD) and the force field of choice, ReaxFF, are discussed, as well as the theory behind each model. The core of the presentation focuses on implementing RMD data from homogenous decomposition into the two models, as well as comparing their kinetics behavior with our in-house simulations. Assumptions and limitations regarding both methods are presented last. So far in the literature, similar multiscale models have already been applied to thermal decomposition and shock simulations of high energy materials, where mechanical loading has been shown to accelerate chemistry. Preliminary results address the role of molecular disorder on reactivity in the context of 2-D thermal hot spots. Date: Friday, December 15, 2017 Time: 9:00 A.M. Place: ARMS 1028