Thursday, March 7 2019
2:00pm - 3:00pm
MRDC Building, Room 4211, 801 Ferst Drive NW, Atlanta, Georgia 30313
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Materials Seminar featuring Dr. John G. Michopoulos

MULTISCALE AND MULTIPHYSICS INTEGRATED COMPUTATIONAL MATERIAL ENGINEERING FOR ADDITIVE MANUFACTURING

John G. Michopoulos, Research Scientist/Engineer
Computational Multiphysics System Lab., Code 6394
Center for Materials Physics and Technology
Material Science and Technology Division
US Naval Research Laboratory

 

Abstract

The presentation will focus on an overview of modeling, simulation (M&S) and experimental activities related to the integrated computational material engineering efforts at US-NRL from the perspective of the multiple length scales and multiple fields involved in layered deposition processes as they relate to Navy applications. The efforts described are a part of  US-NRL’s internally funded effort on the “Science of Layered Deposition Processes”, grand-challenge effort directed by the speaker.

The multiscale issues associated with Additive Manufacturing (AM) will be discussed first in order to lay out the scientific motivation of our efforts. Then, a description of overall analytical, experimental and computational components of the framework under development will be presented. Various aspects and current progress on some of the elements of this framework will be presented.

Emphasis will be given on the solution of the multifield partial differential equations (PDEs) governing the spatio-temporal behavior of AM processes by using various discretization and model order reduction methods. A description of NRL’s AM Multiphysics Discrete Element Method, will also be presented with emphasis on its ability to predict porosity and surface roughness in addition to final part shape for powder-based AM processes. A methodology is introduce to enriched analytical solutions with functionality relevant to the practicalities of AM processes will be introduced and their accuracy and efficiency will be discussed from the perspective of enabling closed loop feedback control in real time. Progress on implicit slicing and multiscale topology optimization for functional tailoring of parts will also be presented. Multiphase field methods for predicting the evolution of the polycrystalline microstructure of multi-element alloys will also be outlined. Connection of process parameters to performance requires utilizing crystal plasticity for generating data-driven constitutive models enabling stress-strain response prediction, examples of which will also be outlined. Finally, AM part qualification methodologies introduced by our group will be presented via the use of automated multi-degree of freedom testing procedures.

Biography

As a Research Scientist/Engineer and head of Computational Multiphysics Systems Lab (CMSL) of the Center for Materials Physics and Technology at the US Naval Research Laboratory (US-NRL), Dr. Michopoulos oversees and actively participates on research efforts involving multi-physics modeling and simulation associated with a plethora of topics in computational and experimental sciences. Some of his current major initiatives include research and development on the science of layered deposition processes,  linking performance to material through data and specification driven methodologies, model order reduction for naval applications, electromagnetic launcher dissipative damage modeling and simulation, mechatronic/robotic data-driven characterization of continua, and multiphysics design optimization. He is a member of the editorial board of several scientific journals and is member of the program committee of several international conferences and has chaired several of them. He has served in the executive committee of the Computers and Information in engineering division of the ASME among others. His technical work and leadership have been recognized by several national and international honors, including the 2015 Excellence in Research award by ASME’s CIE division, the 2015 Innovator Award by Wolfram Inc., and the 2013 “P.S. Theocaris” award for excellence by the National Academy of Athens. He has authored and co-authored more than 270 publications and patents and his a Fellow of the ASME. Dr. Michopoulos holds an M.Sc. In Civil Engineering and a Ph.D. in Applied Mathematics and Mechanics from the National Technical University of Athens, and has pursued post-doctoral studies at Lehigh University on computational multi-field modeling of continua and Fracture Mechanics.

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