Warren Distinguished Lecture Series

Banners that illustrate CEGE's mission and vision hang in the Charles Fairhurst Rotunda

The Warren Distinguished Lecture Series is made possible by a generous, renewing gift by Alice Warren Gaarden in 1961. Since 1989, we have been bringing in accomplished researchers and speakers from around the world to share their work with students, faculty, and friends of CEGE. Please join us for these lectures!

Season Overview

  • September 15  Michael Levin, University of Minnesota
  • September 22  TWO SPECIAL EVENTS
    • Graduate Students 3 Minute Thesis Contest 
    • Sehlin Lecture, Patrick Alexander Ray, University of Cincinnati
  • October       6  Garrett McKay, Texas A&M
  • October     13  Daniel Zielinski, Great Lakes Fishery Commission, Michigan State University
  • October     20  No lecture
  • October     27  Andreas Malikopoulos, University of Delaware
  • November   3  Roberto Ballarini, University of Houston
  • November 10  Lili Du, University of Florida
  • November 17  Nicos Makris, Southern Methodist University
  • December   1  Jinhui Yan, University of Illinois
  • December   8  Susan Brantley, Pennsylvania State University

Upcoming Events

Multi-physics Modeling of 3D Printing of Metallic Materials

A Mixed Diffusive-Sharp Interface Approach for Multi-physics Modeling of 3D Printing of Metallic Materials

A Warren Distinguished Lecture with Jinhui Yan, Civil and Environmental Engineering, University of Illinois Urbana-Champaign

Abstract
Existing metal additive manufacturing (AM) models have difficulty handling the laser-metal interaction and associated boundary conditions (BCs) that significantly influence part quality, such as defect and surface roughness. In this talk, Jinhui Yan presents a sharp-diffusive interface computational method for simulating multiphysics processes in metal AM, focusing on better handling gas-metal interface, where metal AM physics mainly takes place. The framework consists of two components. The first is a mixed interface-capturing/interface tracking multi-physics model to explicitly track the gas-metal interface topological changes without mesh motion or remeshing. The second is an enriched immersed boundary method (EIBM) to impose the critical flow, heat, and phase transition Neumann BCs, which are enforced in a smeared manner in current AM models, on the gas-metal interface with strong property discontinuity. 

Yan demonstrates how the developed model elucidates the fundamental metal AM physics (e.g., melt pool dynamics, keyhole instability, and powder spattering) and predicts critical part quality-related quantities (e.g., defect and surface roughness). The proposed framework’s accuracy is assessed by thoroughly comparing the simulated results against experimental measurements from NIST and Argonne National Laboratory using in-situ high-speed, high-energy x-ray imaging. Yan also reports other important quantities that experiments cannot measure to show the framework's predictive capability.

Speaker
Jinhui Yan is an assistant professor in the Department of Civil and Environmental Engineering (CEE) at University of Illinois at Urbana-Champaign (UIUC). He obtained his BS from Wuhan University (2009), MS from Peking University (2012), and Ph.D. University of California, San Diego (2016). After a two-year postdoc at Northwestern University, he joined the faculty of CEE at UIUC. His research group broadly works on computational mechanics and their applications. He won the ASME Robert M. and Mary Haythornthwaite Young Investigator Award in 2018 and Gallagher Young Investigator Medal from U.S. Association for Computational Mechanics in 2023. The AM model developed by his research group won second place in the 2022 NIST AM benchmark modeling contests. He is a Levenick Teaching Fellow and often enters the list of excellent teachers ranked by the students at UIUC. He currently serves as the vice-chair of the computational fluid dynamics (CFD) and fluid-structure interaction (FSI) technical thrust of USACM and the Computational FSI committee of AMD/ASME.

How Fracking Affects Our Water

How fracking affects our water: Interacting with the public on critical zone science

A Warren Distinguished Lecture with Susan L. Brantley, Geosciences, Pennsylvania State University

Abstract 
“Fracking” of shale at depth has ushered in a new era of natural gas development in the U.S. that has impacted water quality in some locations. In the mid-2000s, public outcry about “fracking” and water quality reached a fever pitch. Today, the pushback continues but is more muted. In this talk, Susan Brantley focuses on what has been learned over the last two decades about water impacts related to shale gas development (including fracking). Much of this talk describes work in Pennsylvania, a state with the longest history of commercial oil extraction in the world, but observations will also be made about the national situation. To investigate this topic required interaction with scientists from government, universities, and private industry as well as non-scientists living in areas of shale gas development. Only with such approaches to involve stakeholders in environmental issues can we learn how to protect the critical zone, the layer of the Earth from the canopy of vegetation to groundwater.

Speaker 
Dr. Susan L. Brantley is the Evan Pugh University Professor and Hubert and Mary Barnes Professor of Geosciences at Pennsylvania State University. As a geochemist, Dr. Brantley focuses on understanding what controls the chemistry of natural water and how water interacts with the rocks, sediments, and soils through which it flows. Some of her recent work has focused on environmental impacts related to the use of hydraulic fracturing in natural gas extraction. Brantley, a member of the National Academy of Sciences and the American Academy of Arts and Sciences, is especially proud to be the mother of a recent Ph.D. recipient in the Department of Earth and Environmental Sciences at the University of Minnesota Twin Cities.

Past Warren Lectures

Inherent Resilience of Large Cities to Natural Hazard

The Inherent Resilience of Large Cities to Natural Hazards: Records, Evidence and Predictions

A Warren Distinguished Lecture with Nicos Makris, Civil Engineering, Southern Methodist University

Abstract
In the view that cities will continue to house the majority of the world’s population at an increasing rate, in association with climate change, in this seminar Markis quantifies urban resilience by examining the response history of the mean-square displacement of the citizens of large cities prior to and upon historic natural hazards strike. During the talk Markis explains how the mean-square displacement from a random (stochastic) process is intimately related to deterministic, emergent time-response functions. The recorded mean-square displacements of large numbers of cell-phone users from the cities of Houston, Miami, and Jacksonville when struck by hurricanes Harvey (2017), Irma (2017) and Dorian (2019), together with the recorded mean-square displacements of the citizens of Dallas and Houston when those cities experienced the 2021 North American winter storm, revert immediately to their pre-event steady-state response, suggesting that large cities when struck by natural hazards are inherently and invariably resilient. The significant number of records presented in this study also validate a mechanical model for cities, recently developed by the speaker, that is rooted in Langevin dynamics and predicts that following a natural hazard large cities revert immediately to their initial steady-state regime and resume their normal, pre-event activities.

Speaker
Nicos Makris is an internationally recognized expert in structural-earthquake engineering and structural mechanics-dynamics, and he is the Addy Family Centennial Professor in Civil Engineering at Southern Methodist University, Dallas, Texas. Makris received his Ph.D. (1992) and Master of Science (1990) from the State University of New York at Buffalo, USA. He holds a Diploma in Civil Engineering from the National Technical University, Athens, Greece (1988). He has previously served on the faculty of the University of Notre Dame, Indiana (1992-1996); the University of California, Berkeley (1996-2005); the University of Patras, Greece (2003-2019); and the University of Central Florida (2014-2018). He has published more than 130 papers in archival journals and has supervised 15 Ph.D. thesis and more than 40 MSc and 5th year Diploma theses. He has served as the Editor of the journal Earthquakes and Structures; the Associate Editor and the Chair of the Dynamics Committee for the Journal of Engineering Mechanics, ASCE. He is a member of Academia Europaea (The Academy of Europe), a Fellow of the American Society of Civil Engineers (ASCE), a distinguished Visiting Fellow of the Royal Academy of Engineering, UK, and a member of the Congress Committee and General Assembly of the International Association of Theoretical and Applied Mechanics (IUTAM). He has been honored with several international prizes and awards including the George W. Housner Structural Control & Monitoring Medal and the J. James R. Croes Medal both from ASCE, the Walter L. Huber Civil Engineering Research Prize from ASCE, the T. K. Hsieh Award from the Institution of Civil Engineers, U.K., the Shah Family Innovation Prize from the Earthquake Engineering Research Institute (EERI), USA, and the CAREER Award from the National Science Foundation, USA. 

During the years 2003-2009, Professor Makris served as the Director of Reconstruction of the Temple of Zeus in Ancient Nemea, Greece:https://www.youtube.com/watch?v=LsxPSeWS52Q

Robust CAV Coordinated In-Vehicle Routing

Robust CAV Coordinated In-Vehicle Routing Leveraging Game Theories, Machine Learning, and Distributed Optimization

A Warren Distinguished Lecture with Lili Du, Civil and Coastal Engineering, University of Florida 

Wireless communication, onboard computation facilities, and advanced sensor techniques  have enabled a well-connected and data-rich transportation system, i.e., connected vehicle system (CVS). Even though the CVS has been granted a great potential to smartly route travelers (or CVs) to avoid traffic congestion, scholars have recognized that as the majority of vehicles become CVs, current real-time information provision and routing methods may worsen traffic congestion, given each CV selfishly and independently chooses its own shortest path. This inherent deficiency of the current routing methods is rooted in the inconsistency between system performance and individual vehicles' route choice behavior. By viewing this, our studies have introduced a novel Coordinated In-Vehicle Routing Mechanism (CRM), which used various game theories to coordinate CVs' routing decisions to address the overreaction phenomenon and the inability to control system performance.

Are configurational forces real forces?

A Warren Distinguished Lecture 
and 2023 Engineering Mechanics Institute of ASCE (EMI) Elasticity Committee Distinguished Lecture

with Roberto Ballarini
Civil and Environmental Engineering, University of Houston

Ballarini shows in paradigmatic examples amenable of generalization that a configurational force can be viewed as the resultant of the contact forces acting on the perturbed shape of an object of substance equivalent to the defect, and evaluated in the limit of the shape being restored to the primitive configuration. The expressions for the configurational forces on cracks and dislocations are in agreement with those determined using classical variational arguments. It is hoped that this somewhat novel approach, which has been applied by Bigoni and coworkers to illustrate configurational forces in structural components, may open a new prospective in the use of configurational forces by permitting their physical and intuitive visualization. 

Combining Learning and Control in Cyber-Physical Systems

A Warren Distinguished Lecture with Andreas Malikopoulos, Civil & Environmental Engineering, Cornell University

In most instances, cyber-physical systems (CPS), represent complex systems with decentralized structure. An ideal model is typically assumed in order to derive optimal control strategies for CPS. Such model-based control approaches cannot effectively facilitate optimal solutions with performance guarantees due to the discrepancy between the model and the actual cyber-physical system. On the other hand, in most CPS there is a large volume of dynamic data, which is added to the system gradually in real time. Thus, traditional supervised learning approaches cannot always facilitate robust solutions using data derived offline. By contrast, applying reinforcement learning approaches directly to the actual CPS might impose significant implications on the safety and robust operation of the system. In this talk, Malikopoulos discusses the challenges of supervised learning and model-based control approaches in several CPS applications, including self-learning powertrain control, power management control of hybrid electric vehicles, and optimal coordination of connected and automated vehicles. Then, Malikopoulos presents a theoretical framework founded at the intersection of control theory and learning that circumvents these challenges in deriving optimal strategies for CPS.

Exploration of the Science Supporting Selective Connectivity at Fish Migration Barriers

A Warren Distinguished Lecture with Daniel Zielinski,  Great Lakes Fishery Commission and Michigan State University

One of the greatest global issues facing fishery managers is the connectivity conundrum, that is, the tension between improving aquatic connectivity for fishery restoration versus using dams and barriers to manage invasive species. Selective connectivity, where organism movement is selective based on restoration or conservation goals, presents a potential solution to the connectivity conundrum. The Great Lakes Fishery Commission and its partners are developing an approach to selective fish passage that integrates fish ecology and biology with engineering at FishPass. The FishPass project will replace the last of four legacy barriers on the Boardman (Ottaway) River, Traverse City, Michigan. The improved barrier and adaptable fishway is designed to develop and test tools to selectively pass desirable fish while blocking and/or removing undesirable fish, like the invasive sea lamprey. The process used to select and configure fish sorting tools will follow an eco-engineering approach inspired by material recycling, and will emphasize automation and the integration of multiple technologies that target sortable attributes of fish (phenological, morphological, behavioral, and physiological). Zielinski provides an overview of FishPass including ongoing research supporting selective fish passage in the Laurentian Great Lakes.

Toward destruction of PFAS through ultraviolet advanced reduction processes

a Warren Distinguished Lecture with Garrett McKay, Civil & Environmental Engineering at Texas A&M University

Photochemistry is the process of light energy being converted into chemical energy, which is initiated by the interaction of molecules with photons. Photochemical reactions play critical roles in natural and engineered environmental systems, such as treatment technologies for abatement of chemical and microbiological contaminants and natural cycling of elements in aquatic systems. The rates and mechanisms of photochemical reactions are governed by properties of the light source, background water matrix, and intrinsic properties of the target contaminant. Garrett McKay and his research group apply these fundamental concepts to study photochemical reactions of important to surface water as well as engineered treatment systems. This presentation will focus on his group’s work to improve the performance of ultraviolet advanced reduction processes (UV-ARP) for the complete destruction of per- and polyfluoroalkyl substances (PFAS) in real world waters. McKay will describe results from studies by his group aimed at quantifying the key processes involved in UV-ARP and how this quantitative knowledge has impacted efforts to enhance PFAS destruction in challenging water matrices.

Multidimensional Risk Management for the Water Sector

Katherine and Arthur Sehlin Memorial Lecture with Patrick Ray, Environmental Engineering, University of Cincinnati 
and 2023 J.S. Braun/Braun Intertec Visiting Professor at the University of Minnesota

Adaptation to climate change is expensive and benefits are not guaranteed. We do not know what amount of greenhouse gases will be emitted by the current generation, nor the impacts the resultant warming will have on our water, agricultural, energy, ecological, and urban systems. We have difficult decisions to make and must not allow uncertainty to paralyze progress toward a better world. Patrick Ray applies concepts of deep uncertainty to example challenges. His aim is to improve decision confidence built on cost-effectiveness, sustainability, equity, and resilience through the critical tool of trade-off analysis. The product must be decision-relevant and interpretable by those who must implement the findings. We have never before had such an opportunity to derive insights from global observations, nor a bigger challenge of complex multidimensionality. Ray shares incremental victories in the realm of water resources decision science and offers a vision for the next decade of needed research. 
 

Max-pressure traffic signal timing: integrating theory and practice

a Warren Distinguished Lecture with Michael Levin, University of Minnesota

Traffic signals are major bottlenecks for urban networks, and traffic signal timing has been studied for decades. However, in 2013, a new paradigm of max-pressure signal timing was introduced, which uses a Markov chain store-and-forward queueing model of traffic flow to mathematically prove that max-pressure control achieves maximum throughput of vehicles. This throughput optimality is shown for a network of max-pressure intersections, not just for individual intersections. 

Sustainable Travel through Smart and Engaged Communities

a Warren Distinguished Lecture with Srinivas PeetaCivil and Environmental Engineering, Georgia Institute of Technology

This talk will discuss ongoing work related to developing a systematic framework and associated innovative methods and models to provide formal pathways for communities to achieve their sustainable travel goals. Solutions to achieve sustainability objectives related to enhancing travel mobility, safety, equity, and access will be discussed using the City of Peachtree Corners (GA) as an immersive living lab.

Reaction-Induced Fracturing Under Subsurface Conditions

a Warren Distinguished Lecture with Wen-lu Zhu, Geology, University of Maryland

The rate and extent of serpentinization and carbonation of ultramafic rocks are a subject of debate. Zhu and team conducted dynamic microtomography experiments to investigate the effects of confinement and pore fluid pressure on hydration of periclase MgO to brucite Mg(OH)2 at subsurface conditions. Their experimental results have important implications in understanding microseismicity in the serpentinization of oceanic crust.