Visiting Scientist

ROHIT RAI

*** **** ****** ** *** **B • State College PA 16803 • 814-***-**** • *****.*.***@*****.***

WORK AUTHORIZATION

Permanent Resident (Green Card Holder)

PROFESSIONAL EXPERIENCE

The Pennsylvania State University

Visiting Scientist July 2010 present

Current research areas are application of artificial neural networks in welding and joining numerical analysis of stresses in welded structures numerical modeling of heat and fluid transport in laser-arc hybrid welding and Monte-Carlo simulations of grain growth.

Other responsibilities include:

• Preparing white papers and grant proposals on numerical modeling of welding processes

• Mentoring two doctoral students in their thesis work on numerical modeling of laser/TIG and friction stir welding processes

• Preparing teaching material for a course on numerical modeling of metallurgical processes

Hawthorne & York International Sep 2008-June 2010

Senior Research and Development Engineer

Responsibilities included providing a materials engineering perspective on armor materials researching existing and new materials suitable for use calculating material properties through molecular dynamics simulations writing project proposals and setting up processes to qualify materials

• Oversaw the upgrade and installation of ultrasonic testing equipment for defect detection and determined the testing protocol

• Worked on product development of ballistic armors with specified performance metrics

• Started the molecular dynamics simulations effort at Hawthorne & York International (HYI). Used LAMMPS code to perform dynamic and static calculations. Employed the MEAM potential to calculate properties such as equilibrium crystal structure elastic constants defect formation and migration energies thermal expansion coefficient and melting point.

• Worked with HyperMesh and LS-DYNA to perform Finite Element Analysis of structural problems

• Prepared Quad Charts White Papers and Project proposals following assessment of Requests for Proposal (RFP) and Broad Agency Announcements (BAA). A Quad Chart on development of armor solutions was accepted by a United States defense research agency and white paper was submitted subsequently.

• Served on Quality initiatives: prepared Quality Assurance documents and served as an Internal Auditor for compliance with ISO9001: 2008

The Pennsylvania State University University Park Aug 2004 Aug 2008

Research Assistant

Teaching Assistant ( Engineering Materials ; Spring 2005 Fall 2006 Spring 2008)

• Developed numerical models in FORTRAN for predicting weld characteristics during high intensity laser beam electron beam and laser-GTA hybrid welding with the formation of deep vapor cavity called keyhole

• Calculated keyhole shape and three-dimensional heat transfer and fluid flow in the weld pool and used genetic algorithm as an optimization tool

• Collaborated with experimentalists from national labs to test the models for several metals and alloys covering a range of material properties and studied the effect of material properties on weld characteristics such as temperature distribution temperature versus time variation solidification characteristics and the keyhole and weld geometries

• Project on Finite Element Analysis of Pulsed Laser Spot Welding using ANSYS

• Wrote Java programs for Monte Carlo Simulations for Phase Separation with 2D Ising Models and for Predator-Prey Systems

Indian Institute of Technology Kharagpur India Jun 2003-May 2004

Undergraduate Researcher

• Used genetic algorithms to optimize roll-scheduling at hot-strip mill to minimize distortion

• Co-authored a paper which figured in the Top 10 Most-Cited Articles from Materials and Manufacturing Processes 2003-2007

Tata Motors Jamshedpur India Jun 2003- Jul 2003

Summer Trainee

• Studied distortion of gear components during heat treatment

EDUCATION

The Pennsylvania State University University Park PA

Ph.D. in Materials Science and Engineering Aug 2004 - Aug 2008

GPA: 3.97/4.0

Thesis: Modeling of heat and fluid transport in high energy beam keyhole mode welding process

Coursework: thermodynamics kinetics transport phenomenon numerical solutions applied to heat transfer and fluid mechanics problems finite elements computational materials science computational physics nano-structured carbon materials

Indian Institute of Technology (IIT) Kharagpur INDIA

Bachelor of Technology (Honors) in Jun 2000 - May 2004

Metallurgical and Materials Engineering

GPA: 8.06/10.0

Thesis: Multi-objective Genetic Algorithm for Roll Schedule Optimization in a Hot Strip Mill

Coursework: A broad range of courses including: physical metallurgy thermodynamics and kinetics deformation behavior mechanical testing materials processing extractive metallurgy electronic materials sensor materials ceramics failure analysis corrosion characterization phase transformations and heat treatment genetic algorithm

PROFESSIONAL ACTIVITIES

Reviewed technical manuscripts for the journals: Metallurgical and Materials Transactions A Science and Technology of Welding and Joining Surface and Coatings Technology International Journal of Heat and Mass Transfer International Journal of Advanced Manufacturing Technology Journal of Zhejiang University-SCIENCE A Optics and Lasers in Engineering Materials Characterization

SKILLS

• Programming Languages: C++ FORTRAN Java

• Technical Software: LAMMPS Tecplot HyperMesh LS-DYNA ANSYS MS Office Suite Dataplot

• Computational Methods: Genetic algorithm based optimization finite element finite difference and control volume methods

• Statistical techniques: Exploratory Data Analysis Design of Experiments Statistical Process Control

HONORS

• McKay-Helm Award by the American Welding Society for the best contribution to the advancement of knowledge of low-alloy steel stainless steel or surfacing welding metals involving the use development or testing of these materials as represented by articles published in the Welding Journal during the calendar year 2009 for my article titled Heat transfer and fluid flow during electron beam welding of 304L stainless steel alloy (2010)

• Kennametal Fellowship for academic excellence which is open to over 150 graduate students at The Pennsylvania State University (2007)

• Ranked amongst the top 1.5% of students appearing for Joint Entrance Examination for Indian Institute of Technology (IIT) from all over India (2000)

• 6th rank in the Regional Mathematics Olympiad in the state of Uttar Pradesh INDIA (1997) which is open to over 100 000 students

• Lead a group of over 250 students as Senior Cadet Under-Officer for the Air Wing of National Cadet Corps at IIT Kharagpur (2000-2001)

CONFERENCES PRESENTATIONS AND PROCEEDINGS

1. Poster presentation at Defense Advanced Projects Research Agency (DARPA) proposers workshop in Washington VA 2009.

2. R. Rai T. A. Palmer J. W. Elmer T. DebRoy Modeling of Heat Transfer and Fluid Flow during Keyhole Mode Electron Beam Welding 1st International Electron Beam Welding Conference Nov. 17-18 2009

3. B. D. Ribic R. Rai T. A. Palmer and T. DebRoy Arc-Laser Interactions and Heat Transfer and Fluid Flow in Hybrid Welding submitted for publication in the proceedings of 8th International Conference on Trends in Welding Research 2008

4. R. Rai J. W. Elmer T. A. Palmer and T. DebRoy Heat Transfer and Fluid Flow During Keyhole Mode Laser Welding of Tantalum Ti-6Al-4V 304 Stainless Steel and Vanadium AWS conference 2007

5. R. Rai S. M. Kelly R. P. Martukanitz T. DebRoy Experimental and computational investigation of fusion zone geometries during autogenous keyhole mode laser welds ICALEO Congress Proceedings 515-***-****

JOURNAL PUBLICATIONS

1. R. Rai T. A. Palmer J.W. Elmer and T. DebRoy Heat transfer and fluid flow during electron beam welding of 304L stainless steel alloy Welding Journal vol: 88 pages: 54-s 61-s yr: 2009

2. R. Rai P. Burgardt J. O. Milewski T. J. Lienert and T. DebRoy Heat transfer and fluid flow during electron beam welding of 21Cr 6Ni 9Mn steel and Ti 6Al 4V alloy Journal of Physics D: Applied Physics vol: 42 article # 025503 yr: 2009

3. B. Ribic R. Rai and T. DebRoy Numerical simulation of heat transfer and fluid flow in GTA/Laser hybrid welding Science and Technology of Welding and Joining vol:13 (8) pages: 683-693 yr: 2008

4. R. Rai S.M. Kelly R.P. Martukanitz T. DebRoy A convective heat transfer model for partial and full penetration keyhole mode laser welding of a structural steel Metallurgical and Materials Transactions A vol: 39 (1) pages: 98-112 yr: 2008

5. R. Rai J.W. Elmer T.A. Palmer T. DebRoy Heat transfer and fluid flow during keyhole mode welding of tantalum Ti-6Al-4V 304L stainless steel and vanadium Journal of Physics D: Applied Physics vol: 40 pages: 5753-5766 yr: 2007

6. R. Rai G.G. Roy T. DebRoy A computationally efficient model of convective heat transfer and solidification characteristics during keyhole mode laser welding Journal of Applied Physics vol: 101 article #: 054909 yr: 2007

7. R. Rai T. DebRoy Tailoring weld geometry during keyhole mode laser welding using a genetic algorithm and a heat transfer model Journal of Physics D: Applied Physics vol: 39 pages: 1257-1266 yr: 2006

8. R. Nandan R. Rai R. Jayakanth S. Moitra N. Chakraborti A. Mukhopadhyay Regulating crown and flatness during hot rolling: A multi-objective optimization study using Genetic Algorithms Materials and Manufacturing Processes vol: 20(3) pages: 459-478 yr: 2005

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