Archives—October 2013

MEEM Graduate Seminar: Guaranteeing Accurate Decoupled Approximations Via Structural Design


The Department of Mechanical Engineering – Engineering Mechanics Graduate Seminar; Thursday, Oct. 31, 2013 4:00 – 5:00 p.m. Room 112, ME-EM Bldg.;
Professor Cornel Sultan, Aerospace and Ocean Engineering Department, Virginia Tech

Title: Guaranteeing Accurate Decoupled Approximations Via Structural Design

Coordinate coupling raises serious modeling, numerical, analysis, control
design problems that grow with the size of the system. Decoupled dynamic equations
facilitate all of the above processes since each equation can be treated independently.
Unfortunately, due to the inherent heterogeneity typical of most practical, complex
systems, these are not naturally decoupled so developing sufficiently accurate
decoupled approximations is of major interest.
In this talk the issue of building such accurate decoupled approximations is
addressed by leveraging concepts from control theory. Specifically, system gains (e.g.
energy gain, peak to peak gain) are used to characterize the approximation error. Then
some system parameters are selected to minimize this approximation error. The
advantage of using system gains is that the decoupling approximation is guaranteed to
be accurate over an entire class of signals (e.g. finite energy/finite peak signals).
These ideas are illustrated on tensegrity structures which are designed to yield
accurate decoupled linear models with respect to all signals of finite energy and finite
peak. Further analysis corrects several misconceptions regarding decoupling, system
properties, and control design.

Cornel Sultan holds M.S. in Mathematics, Ph.D. in
Aerospace Engr. from Purdue University (1999) and
has been affiliated, among others, with Harvard
Medical School and United Technologies Research
Center. Currently he is an Assistant Prof. in the
Aerospace and Ocean Engineering Department at
Virginia Tech where his principal research activities
are in tensegrity, membranes, rotorcraft, energy
harvesting, and coordinated control. He received a
NSF CAREER Award in 2010.




MEEM Graduate Seminar: New inorganic glass/organic polymer hybrid materials

The Department of Mechanical Engineering – Engineering Mechanics Graduate Seminar: Professor Joshua Otaigbe, PhD, CEng, CSci, FIMMM School of Polymers and High Performance Materials University of Southern Mississippi; Thursday, Oct. 24, 2013 4:00 – 5:00 p.m. Ro om 112, ME-EM Bldg.

Title: New inorganic glass/organic polymer hybrid materials with improved properties— Current status and future prospects

The physical modification of polymer structure and properties via polymer blending and reinforcement is a common practice in the plastics industry and has a large economic advantage over synthesizing new polymeric materials to fulfill new material needs. In this context, a new class of inorganic glass/organic polymer hybrids with enhanced benefits has been developed by blending low-Tg phosphate glasses with polymeric materials in the liquid state, to afford new hybrid materials with significant improvements in properties that are impossible to achieve from classical polymer blends and composites. Because of their facile synthesis and desirable characteristics, these phosphate glass/polymer hybrid materials may be model systems for exploring feasibility of new routes for driving inorganic glasses and organic polymers to self- assemble into useful materials. Conceptually, it may even be possible to use block copolymers, with one block being miscible with Pglass, to perform self-directed assembly of nanostructured hybrids, where the Pglass is confined solely to one phase. In this talk, I will review some new insights into the structural dynamics, melt rheology & processing, molecular relaxation processes, and phase behavior of a few representative examples of these unique hybrid materials with prescribed rheological properties, macromolecular structure and function. The unanswered questions will be discussed to guide future research directions, and facilitate progress in this emerging area.

Joshua Otaigbe earned his PhD from the University of Manchester Institute of Science and Technology, UK, thus starting a circuitous career that spanned three continents. He has been involved in most areas of chemical engineering and advanced materials science including research in the areas of polymer engineering and materials science. His research blends chemical engineering sciences with materials structure and property principles to better understand and improve processes for advanced polymeric materials. Joshua worked as a Project Leader for Corning Incorporated in New York in the Corporate Research, Development and Engineering Division. He also held academic positions at the University of Alberta, Canada, and the University of Benin, in Nigeria. At Iowa State University he became a tenured Associate Professor of Chemical Engineering and of Materials Science & Engineering, and Leader of Polymers and Composite Research Group. He influenced the design of the materials engineering curriculum at Iowa State to include a polymer engineering option. In 2002, he joined his current position with The University of Southern Mississippi as a Professor of Polymer Engineering and Science where he is active in promoting the teaching of materials science and engineering as the study of all aspects the of materials as a whole rather than separating their chemical, physical, and engineering aspects. Joshua holds seven patents and has published more than 110 refereed scientific journal papers. Joshua is the founder of Flaney Associates LLC, a company that provides technical consulting to polymer, chemical and advanced materials companies on the engineering of manufacturing processes and products including providing materials/chemicals expert witness for attorneys and insurance professionals for cases on materials engineering, chemical processes/products, and for issues related to industrial and consumer materials science and engineering. Joshua has been awarded invited visiting professorships in the Swiss Federal Institute of Technology (ETH-Zurich), the French Engineering Universities, Institut National des Sciences Appliquées (INSA) in Lyon, and in the Université Jean Monnet in Saint-Etienne. He is a Fellow of the Institute of Materials, Minerals & Mining and Fellow of Society of Plastics Engineers. A recipient of the U.S. National Science Foundation CAREER Award and the Best Paper-Polyolefins Award from the Thermoplastic Materials and Foams Division of the Society of Plastics Engineers. He was an honored member in Who’s Who of American Inventors (1998-1999 edition). In the last few years, Joshua is the Principal Investigator of a number of research grants and contracts from National Science Foundation and industry including Chemtura Corporation, a leading global manufacturer of flame retardant additives for plastics. Most recently, Joshua was awarded the Fulbright-Tocqueville Distinguished Chair in France for 2013-2014, an appointment reserved for eminent scholars with substantial experience and publications in their respective fields. Funding for the ME-EM Graduate Seminar Series is provided by the Department of Mechanical Engineering – Engineering Mechanics


Stepping Out in Style: Michigan Tech Researchers Developing an Artificial Leg with a Natural Gait

Walking is tricky business, as any toddler knows. And while most artificial feet and limbs do a pretty good job restoring mobility to people who have lost a leg, they have a ways to go before they equal the intricacy of a natural gait. As a result, over half of all amputees take a fall every year, compared to about one-third of people over 65.

In cooperation with a Mayo Clinic scientist, researchers at Michigan Technological University are taking a giant step toward solving the problem. They are making a bionic foot that could make an amputee’s walk in the park feel, well, like a walk in the park.

The secret lies in the ankle. Mo Rastgaar, an assistant professor of mechanical engineering–engineering mechanics, and PhD student Evandro Ficanha are working on a microprocessor-controlled ankle-foot prosthesis that comes close to achieving the innate range of motion of this highly complex joint.
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MEEM Graduate Seminar: Bioinspired Nanoengineering of Multifunctional Surfaces

The Department of Mechanical Engineering – Engineering Mechanics Graduate Seminar: Professor Chang-Hwan Choi Stevens Institute of Technology, Thursday, Oct. 17, 2013 4:00 – 5:00 p.m. Room 112, ME-EM Bldg.

Title: Bioinspired Nanoengineering of Multifunctional Surfaces

Nature such as plants, insects, and marine animals uses three-dimensional (3D) micro/nano-textured surfaces with tailored surface wettability and mechanical pliability in their components (e.g., leaves, wings, eyes, legs, and skins) for multifunctional purposes such as self-cleaning, low-friction, antifouling, anti-icing, and anti-reflection. As scientific quests and engineering applications reach down to such a nanometer scale inspired by the nature, there is a strong need to fabricate 3D nanostructures with good regularity and controllability of their pattern, size, and shape. In many applications, furthermore, the nanostructures are not useful unless they cover a relatively large area and the manufacturing cost is within an acceptable range. The first part of this presentation will introduce effective 3D nano-patterning and fabrication techniques to create well-regulated nanostructures over a relatively large substrate area of various types of substrate materials. Such large-area 3D nanostructures with tailored structural dimensions and geometries can open new application possibilities in many areas. The rest of the talk will present a few examples of novel applications using the 3D nanostructures, including hydrodynamic drag reduction, anti-biofouling, anti-icing, and anti-corrosion.

Future potential applications of the 3D nanostructures to the other areas will also be discussed briefly, including self-assembly of nanomaterials and nanofluidic energy harvesting.

Dr. Chang-Hwan Choi is currently working as an Associate Professor in the Department of Mechanical Engineering at the Stevens Institute of Technology. He acquired his BS (1995) and MS (1997) in Mechanical & Aerospace Engineering from Seoul National University in Korea. He also earned his MS in Fluids, Thermal, and Chemical Processes from Brown University in 2002. Dr. Choi received his PhD in Mechanical Engineering from the University of California at Los Angeles (UCLA) in 2006, specializing in MEMS/Nanotechnology and minoring in Fluid Mechanics and Biomedical Engineering. He has two-year (1996, 2000) work experience at Korea Aerospace Research Institute and three-year (1997-1999) teaching experience at Chandrakasem Rajabhat University in Thailand. His current research activities include large-area nanopatterning and 3D nanofabrication, fluid physics and heat transfer at nanoscale interfaces, microfluidic self-assembly of nanomaterials, nanofluidic energy harvesting, and cell-material interactions, funded by various federal agencies in US (NSF, DARPA, ONR, ARMY, and DOE) and industries. He has recently been named as a recipient of the 2010 Young Investigator Program (YIP) award by the US Office of Naval Research (ONR) for his efforts in the development of 3D nanostructures for hydrodynamically efficient anti-corrosion surfaces and highlighted in Nature (http://www.nature.com/naturejobs/2010/100520/pdf/nj7296-385a.pdf).



MEEM Graduate Seminar: Modern Product Development

The ME-EM graduate seminar speaker for Thurs. Oct. 10 at 4:00 in 112 MEEM is Dr. Bashar AbdulNour, the technical manager of the Thermal Analysis and Validation Group at General Dynamics Land Systems. His presentation is entitled ‘An Engineering Insight into Modern Product Development’.

Modern product development involves a disciplined process with milestones and key design maturity deliverables. In recent years, the complexity and pace of product development has followed the advancements in science and technology, customer demands, and increased market competition. The process starts with translating the requirements gathered from the Voice of the Customer (VOC), government regulations, and corporate standards into engineering specifications. Design concepts are selected and narrowed down to the final design based on the judgment of the collected data. The complexity can be managed by applying systems engineering principles to provide the framework throughout the process. A lean and structured engineering approach with focus on the target customer has been deployed in many industries as a change agent. Six Sigma emerged as the primary enabler to help improve design and manufacturing efficiencies and deliver value to the entire enterprise. Experimental design and failure mode avoidance techniques are increasingly used to produce a robust design that delivers the required performance despite noise conditions.

The continued expansion in the use of modeling and simulation (M&S) tools in design and development pushed the pace even further in order to decrease the time-to-market and reduce cost by replacing expensive prototyping and testing. Also, the increased utilization of M&S moved its implementation further upstream
in the development process. High-fidelity simulations such as CFD and thermal modeling are being used to accurately predict complex airflow and temperature distributions. Multi-physics modeling and fluid-solid interaction are being utilized to simulate complex problems such as phase-change and NVH. Coupled simulations using several tools are being automated to run design iterations and “what if” scenarios; for example, lumped-parameter (1-D) simulation for thermal loading along with CFD solution for vehicle interior and underhood airflow. In addition, in some industries such as off-highway, military, and space vehicles, M&S became quite critical since it is prohibitively expensive to build a large number of prototypes. Alternatively, prototypes are made available only for design validation and sign-off. The innovative use of M&S for virtual prototyping and certification will allow for more design iterations yielding optimized performance, reduced power consumption, and enhanced quality.

Dr. Bashar AbdulNour is currently the technical manager of the Thermal Analysis and Validation Group at General Dynamics Land Systems. He leads a team of analysis and testing engineers working on the design and development of thermal systems for all types of military vehicles. He also manages three state-of-the-art thermal laboratories. Concurrently, he is an Adjunct Professor at Wayne State University. His areas of expertise are Computational Fluid Dynamics (CFD), thermal management, and systems engineering. He is a certified Design for Six Sigma (DFSS) Black Belt. Dr. AbdulNour holds three graduate degrees from Michigan State University including a Ph.D. in Mechanical Engineering. He was a tenure-tracked Assistant Professor of Mechanical Engineering at the University of Wyoming. He later joined Ford Motor Company where he developed extensive knowledge of vehicle climate control and powertrain cooling engineering, powertrain attributes, CAE, as well as the technical methods used in product development. His hands-on work with analysis and simulation tools, technology development, and testing techniques earned him diverse engineering and management expertise with progressive responsibilities. Dr. AbdulNour has over 53 published journal and conference papers. He has been the chairman of twenty-three technical sessions at national and international conferences and has given more than 60 technical presentations. Also, he has been the co-organizer of the Climate Control Session of SAE International Congress since 2001, and was the technical keynote speaker in 2010, 2011, and 2013.