EMI/PMC 2012 is pleased to showcase a unique format for keynote presentations at this year's conference. On each of the three days of the joint conference, we will have a keynote to begin the day and a second keynote following lunch. In these keynote sessions, our distinguished speakers will give their presentation and be flanked by a pair of experts in the field that will further engage the speaker and the audience to stimulate a more interactive discussion. This year's keynotes will canvas a wide range of topics relevant to the themes of this year's joint conference to showcase the new directions our community is taking in addressing grand challenges in mechanics. Learn more about our keynotes and their topics by clicking the respective tabs below.
MONDAY, JUNE 18, 2012 (1:30-2:30 pm)
Challenges In Modeling Earthquake Effects
Jonathan D. Bray, Ph.D, P.E.
Earthquakes can destroy our cities and kill thousands of people. There have been tremendous advances in our understanding and modeling capabilities of earthquake processes and effects over the last few decades. Yet, many challenges remain that require advancements in our characterization and modeling capabilities. Some of these challenges include modeling the phenomena of surface fault rupture, soil liquefaction, and soil-structure interaction (SSI). Effective design strategies can be developed if we can confidently capture key mechanisms and understand clearly the limitations of our analyses. The surface fault rupture hazard has been analyzed primarily by finite element and finite difference methods, but continuum mechanics has limitations that could be avoided with robust discrete element methods that capture the particulate nature of granular materials. Soil liquefaction is a complex granular-pore fluid interaction problem that we largely capture through empirical methods due to the uncertainties involved in site characterization and geotechnical modeling of this phenomenon. The nonlinear responses of structures and soils as they respond to intense ground shaking need to be captured in a unified approach to improve SSI modeling. Moreover, buildings do not typically stand isolated in our urban centers, but instead our city blocks have closely spaced buildings. Thus, structure-soil-structure interaction (SSSI) effects need to be explored. Some of these challenges are discussed in this lecture.
Panelists: Erik Vanmarcke, Princeton University & George Deodatis, Columbia University
Jonathan Bray is a Professor of Geotechnical Engineering at the University of California, Berkeley. He earned engineering degrees from West Point (B.S.), Stanford University (M.S.), and U. C. Berkeley (Ph.D.). He has been a registered professional civil engineer since 1985, and he has served as a consultant on several key engineering projects, peer review panels, and legal cases. Prof. Bray has authored more than 250 research publications. His expertise includes surface fault rupture, ground motions, liquefaction, seismic slope stability, and post-earthquake reconnaissance. He has earned several honors, including the Joyner Lecture, Prakash Research Award, ASCE Huber Research Prize, Packard Foundation Fellowship, and NSF Presidential Young Investigator Award.
TUESDAY, JUNE 19, 2012 (1:30-2:30 pm)
Turbulence modelling for strongly detached high-Reynolds number flows around bodies with applications in fluid-structure interaction
Marianna Braza, Ph.D
In the present talk, we will examine recent turbulence modelling approaches for the simulation of highly detached unsteady flows around bodies at high Reynolds number with emphasis to advanced statistical and hybrid methods. The structural properties of non-equilibrium turbulence in the near - region will be discussed, as well as their impact on the modification of the turbulence scales and their consequence in specific turbulence modelling developments. Emphasis will be given in the prediction of the aerodynamic global parameters, their predominant frequencies and the pressure fluctuations responsible for acoustic noise, as well as of thin shear-layer prediction past the separation points. These modelling developments will include aspects of inverse cascade and of upscale modelling. Applications will be provided for flows around fixed bluff bodies, including also fluid-structure interaction phenomena arising from MIV (Movement Induced Vibration).
Panelists: Yukio Tamura, Tokyo Polytechnic University & Gretar Tryggvason, University of Notre Dame
Marianna Braza (PhD INPT, 1981) received her Ph.D. in Fluid Mechanics from the National Polytechnic Institute of Toulouse (INPT) in 1981. She was appointed as Director of Research at the National Center for Scientific Research (CNRS), at the "Institut de Mécanique des Fluides de Toulouse" (IMFT) in 2001, after holding research position of "Chargée de Recherche" for four years at CNRS-IMFT. Founded in 1918, the IMFT is one of the leading research laboratories in Europe and the research carried out at the IMFT involves scientific domains ranging from energy, transport (especially aeronautics), process, environment and health. Her current responsibilities involve leadership of the research team "Fluid-Structure interaction under Turbulent flows'' in IMFT, including several permanent and invited faculty members, doctoral students and postdoctoral fellows. Her research interests are in flow physics and modeling of turbulent aerodynamic flows, and fluid-structure interaction. She has received three scientific awards (CRAY-Research, France, 1987); (Académie des Sciences et de Belles Lettres de Toulouse, 1988); (IBM - Calcul Numérique Intensif, 1991). Currently, she is the coordinator of several working groups in federative European Research Programmes of the 6th and 7th Framework (FP7) in areas related to aeronautics, fluid-structure interactions and unsteady flow physics of shock waves, and she coordinates a national aeronautics research program on Electroactive Morphing.
MONDAY, JUNE 18, 2012 (9:00-10:00 am)
Stochastic Modeling of Flow Problems in High Dimensions
George Em Karniadakis, Ph.D
Quantifying uncertainty in flow systems as well as coupled flow-structure taxes computationally resources heavily so only very few stochastic simulations of realistic flow systems have been performed so far. In problems of industrial complexity, e.g. in flow design, there maybe many uncertain parameters or stochastic excitations with relatively short correlation length, hence requiring many dimensions in parametric space. In this talk, we will review existing methods for tackling the curse-of-dimensionality and we will propose different algorithms that can overcome it. In particular, simulations of stochastic flow problems with more than 100 dimensions will be presented.
Panelists: Muhammad Hajj, Virginia Tech & Joseph Powers, University of Notre Dame
George Karniadakis received his S.M. (1984) and Ph.D. (1987) from Massachusetts Institute of Technology. He was appointed Lecturer in the Department of Mechanical Engineering at MIT in 1987 and subsequently he joined the Center for Turbulence Research at Stanford / Nasa Ames. He joined Princeton University as Assistant Professor in the Department of Mechanical and Aerospace Engineering and as Associate Faculty in the Program of Applied and Computational Mathematics. He was a Visiting Professor at Caltech (1993) in the Aeronautics Department. He joined Brown University as Associate Professor of Applied Mathematics in the Center for Fluid Mechanics on January 1, 1994. He became a full professor on July 1, 1996. He has been a Visiting Professor and Senior Lecturer of Ocean/Mechanical Engineering at MIT since September 1, 2000. He was Visiting Professor at Peking University (Fall 2007). He is a Fellow of the Society for Industrial and Applied Mathematics (SIAM, 2010-), Fellow of the American Physical Society (APS, 2004-), Fellow of the American Society of Mechanical Engineers (ASME, 2003-) and Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA, 2006-). He received the CFD award (2007) by the US Association in Computational Mechanics.
TUESDAY, JUNE 19, 2012 (9:00-10:00 am)
Molecular Interactions Impact the Mechanics of Nanomaterials: A Paradigm Shift in Mechanics
Dinesh R. Katti, Ph.D
This talk will describe the role of molecular interactions and nano and microarchitecture on the mechanics of Nanomaterials that include biological and synthetic nanocomposites and smectite clays. The presentation will include examples of three nanocomposite materials, 1) nacre, the inner layer of seashells, 2) bone, 3) polymer-clay-nanocomposites and swelling clays, and will describe the mechanisms that control mechanical properties, using innovative multiscale modeling and experimental techniques. The important discoveries and key findings made by the Katti group that reveal the mechanisms that lead to unique properties exhibited by these nanomaterials will be described. The modeling and experimental techniques bridge a wide range of length scales from molecular to nano/micro to macroscale using ab-inito, molecular dynamics, discrete element and finite element for modeling; and spectroscopy, electron microscopy and nanomechanical testing for experimental investigation. These techniques have led to simulations based materials design of synthetic nanocomposite materials. The significant role of nanoscale proximity in influencing molecular interactions and hence the mechanics of Nanomaterials is revealed for structures in nature such as sea shells and bone as well as engineered nanocomposites and is thus a characteristic of nanosystems.
Panelists: Zdeněk P. Bažant, Northwestern University & Christian Hellmich, Vienna University of Technology
Prof. Dinesh Katti received his B.S. degree in civil engineering from National Institute of Technology, Srinagar, India, M.S. degree in geotechnical engineering from Indian Institute of Technology, Bombay, India and Ph.D. in civil engineering from University of Arizona, Tucson. After receiving his doctoral degree in 1991, he worked in the industry as a geotechnical consulting engineer in two companies in the Seattle area, Dames and Moore and Terra Associates where he worked on over 125 projects. He joined North Dakota State University in the department of civil engineering in the fall of 1996 as an associate professor. In 2002 he was promoted to the rank of full professor. He served as chairman of the department of civil engineering at NDSU from 2004 to 2009. During the same period, he served as Associate Dean of Research for the College of Engineering and Architecture.
WEDNESDAY, JUNE 20, 2012 (9:00-10:00 am)
Structural Health Monitoring Systems: Advances and Impediments to Full Implementation
Anne S. Kiremidjian, Ph.D
Structural health monitoring (SHM) has received increasing interest in the research community and in the past two decades significant advances have been made towards the development of sensors and damage algorithms that are specific for civil infrastructure systems. Recent research has also demonstrated that wireless sensing networks can be successfully used for SHM. With our civil infrastructure greatly deteriorating, the need for monitoring has amply been demonstrated. In addition, owners of critical facilities such as nuclear power plants, oil refineries and chemical plants that are reaching their design life would like to extend their life due to economic conditions. Earthquakes, hurricanes and floods continue to cause extensive damage to infrastructure components resulting in extensive economic losses.
In order for structural health monitoring (SHM) systems to be economically viable, they should serve multiple purposes. The first is to determine damage from an unusual or extreme load. The second is to determine strength degradation due to long term deterioration from every-day loads and environmental effects. A third is to obtain information on the structural parameters or the system in its as-built conditions, which are likely to be very different from the design parameters thus improving future designs, as well as enabling life-cycle analysis and maintenance planning. Such SHM systems are optimal and justifiable for implementation.
Over the past two decades significant advances have been made in the development of wireless sensors deploying micro-electro-mechanical (MEMS) and nano- sensors, the design of complex wireless communications networks, and local and global data interrogation and interpretation methods. Many challenges, however, still remain particularly related to reliable diagnosis and prognosis. Moreover, synthesis of the diagnosis and prognosis in a form that is understandable by users is still a major obstacle to widespread implementation. In this presentation, we will describe the main components of a comprehensive structural health monitoring of civil infrastructure systems and will focus on the development of advanced damage diagnosis methods. Examples from current research at Stanford’s Intelligent Sensing Laboratory that has focused on the development of damage-diagnosis methods using statistical pattern recognition methods will be summarized. These will include damage identification and quantification algorithms using autoregressive and wavelet based models. Distinction will be made between algorithms for diagnosing damage from long term deterioration and from extreme events that cause non-stationary dynamic loads. A novel damage identification method using change point statistics will be also be included. Example applications illustrating the various algorithms will include verification with data from reinforced concrete and steel frame laboratory test structures. Based on this research, key obstacles to implementation will be identified and discussed.
Co-Authors: Hae Young Noh, Postdoctoral Researcher, and Ram Rajagopal, Assistant Professor, Department of Civil and Environmental Engineering, Stanford University
Panelists: Andrew Smyth, Columbia University& Shirley Dyke, Purdue University
Anne S. Kiremidjian is a Professor of Civil and Environmental Engineering at Stanford University. From 1987 to 2002 she served as the Director and Co-Director of the John A. Blume Earthquake Engineering Center at Stanford University. Dr Kiremidjian received her B.S. degree from Columbia University in Civil Engineering and her M.S. and Ph. D. degrees from Stanford University in Structural Engineering. Professor Kiremidjian has been on the faculty at Stanford since 1978 where she teaches courses in structural analysis, earthquake engineering, probabilistic methods and structural reliability analysis. Her research over the years has focused on stochastic modeling of earthquake events, site hazard characterization, ground motion modeling, earthquake damage and loss estimation, structural damage modeling, risk analysis of transportation systems, reliability analysis of industrial systems, and damage detection algorithms. Currently she is working on the development of distributed remote sensing systems for structural damage monitoring using micro-electro-mechanical sensors and embedded diagnostic algorithms utilizing statistical pattern recognition methods. The second area of current research is the development of time dependent risk assessment methods using remotely sensed data.
WEDNESDAY, JUNE 20, 2012 (1:30-2:30 pm)
New Trends in Valvular and Cardiac Tissue Constitutive Models
Michael S. Sacks, PhD
Our laboratory has pioneered morphologically-driven constitutive models for heart valve tissues. Our current work focuses on extending these models to increasing realism based on novel structural data currently obtainable from novel optical studies under controlled loading. Moreover, we are extending these studies to cellular deformation to link with the underlying mechanobiological responses of the constituent cellular population, e.g., recent work on myocardium modeling, a field that as yet has no acceptable model for actively contracting tissue. Computational implementation of these models represents the major next step in the understanding of biological tissues, and is essential for the understanding of the underlying processes for growth and remodeling, and hence the mechano-growth governing laws. Recent results of these approaches using in-vivo engineered tissue remodeling will also be presented.
Panelists: Roberto Ballarini, University of Minnesota & Hsueh-Chia Chang, University of Notre Dame
Michael Sacks is professor of biomedical engineering and holder of the W. A. "Tex" Moncrief, Jr. Simulation-Based Engineering Science Chair I. He is also director of the ICES Center for Cardiovascular Simulation-based Engineering. Sacks formerly held the John A. Swanson Chair in the Department of Bioengineering at the University of Pittsburgh. He earned his B.S. and M.S. in engineering mechanics from Michigan State University, and his Ph.D. in biomedical engineering (biomechanics) from The University of Texas Southwestern Medical Center at Dallas.
In 2006, he was selected as one of the Scientific American top 50 scientists. In 2009, he won the Van C. Mow Medal from the American Society of Mechanical Engineers (ASME) Bioengineering Division and the Chancellor's Distinguished Research Award at the University of Pittsburgh. He is a fellow of ASME and the American Institute for Medical & Biological Engineering, and an inaugural fellow of the Biomedical Engineering Society. He is currently editor of the "Journal of Biomechanical Engineering," and serves on the editorial board for 27 other journals.
He is a world authority on cardiovascular biomechanics, with a focus on the quantification and simulation of the structure-mechanical properties of native and engineered cardiovascular soft tissues. He is a leading authority on the mechanical behavior and function of heart valves, including the development of the first constitutive models for these tissues using a structural approach. He is also active in the biomechanics of engineered tissues, and in understanding the in-vitro and in-vivo remodeling processes from a functional biomechanical perspective. His research includes multiscale studies of cell/tissue/organ mechanical interactions in heart valves and he is particularly interested in determining the local stress environment for heart valve interstitial cells. His recent research has included developing novel constitutive models of right ventricular myocardium that allow for the individual contributions of the myocyte and connective tissue networks.