News & EventsDepartment Events
Events
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Feb26
EVENT DETAILS
lessOptimizing Structures
Abstract:
Building structural components traditionally comprise a significant share of the natural resources used on a construction project. Improvements in structural design procedures can potentially result in significant reductions in use of these materials, as well as reducing construction costs. Structural optimization techniques may dramatically improve the material efficiency of buildings, satisfying performance criteria with more cost-effective designs. Theoretical approaches to structural optimization have been used in the past with some success. Trial and error is still used often to refine structural member sizes and geometries. However advances in computational speed and software development have simplified the process. While generally quite complex, optimization routines can be used to quickly evaluate alternative systems by significantly reducing the number of feasible solutions.
WSP has applied optimization theories to actual project components using a number of different procedures, such as size optimization of individual members, shape optimization (form finding), and topology optimization (spatial distribution of structural members). The processes used for these studies will be presented to illustrate the capacity structural optimization has to improve our final work products. Studies include sizing of shear walls and bracing elements for lateral load resistance, shaped roofs, and other complex geometries whose optimal solutions are not readily apparent.
Biography
Jim Swanson is Director of Structural Engineering for the Chicago office of WSP. Since receiving his bachelor’s degree from Northwestern University and master’s degree from Purdue University, Jim has spent his entire 35-year career practicing in the design of building structures. His work features extensive experience in state-of-the art high rise, long span and transportation structures. Jim has engineered a wide range of complex projects, including the Hyatt Headquarters in Chicago, the Samsung Beijing Headquarters, and the VietinBank Business Center towers in Hanoi. His far-ranging technical expertise has also helped owners and teams on a number of Concept advisements, Peer Reviews and Competitions around the world.
TIME Wednesday, February 26, 2020 at 6:00 PM - 7:00 PM
LOCATION A230, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering
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Feb28
EVENT DETAILS
lessFE Analyses for Developing Retrofit Concepts under Extreme Dynamic Environments
ABSTRACT:
The primary objective of a mitigation design is to prevent substantial deformation of structural elements in hopes of preventing structural collapse, progressive collapse and damage and, thus, reducing loss of life. Mitigation scheme options are depended on the type and construction of a structure. In this particular presentation, we’ll restrict ourselves to multistory structures of typical steel and concrete construction practice.
Mitigating the effects of closed-in detonations to prevent breach alone is a formidable task. Past evaluations of mitigation designs involved absorbers and sacrificial barriers as well as facade and internal hardening options. Selecting a blast mitigation design, however, to reduce the effects of closed-in detonations traditionally addresses only the pressure and impulse loading effects on the facade of the structure under consideration. Secondary effects which are overlooked involve the build up of internal pressures and debris loading. Specialized experimental setups were designed to study these secondary effects.
This presentation exposes some of these issues and provides insights as to potential remedies to the problems stated earlier. Experimental measurements and numerical analyses are shown to compare the robustness of the current FE codes when used as predictive tools.
BIO
Dr. Papados education includes a BS in Civil Engineering (CE), a MS in CE/Structures, and a PhD in Computational and Applied Structural Mechanics..
Dr. Papados is currently a Senior Research Engineer for the Department of Defense (DoD). He has been involved primarily in military project since 1993 and a major portion of his work is classified. Management of new projects and maintenance of existing ones is part of his tasks.
Prior to his current position, Dr. Papados was a Research Structural Engineer with the U. S. Army Engineer Research and Development center. Portion of his work involved high fidelity large-scale computations to enhance counter terrorist measures for a variety of high profile structures. He was also involved in code development and validation.
While Dr. Papados was with the U. S. Army Research Laboratory the emphasis of his work rested on the enhancement of the current scalable software, improvement of constitutive modeling, and improvement of mesh generation methods suited for parallel machines as well as the development of new programs under the auspice of the DoD.
Dr Papados served with the Waterways Experiment Station between June, 1993 and May, 2000. His main duties included development, coordination, and completion of blocks of large scope of work. Areas of involvement included constitutive modeling, massively parallel code implementation, and development, implementation, and benchmarking of explicit FEA codes on scalable machines under the Common High Performance Computing Software Support Initiative (CHSSI).
Dr. Papados served as adjunct professor, visiting professor and assistant professor at a number of universities. He belongs to several national and international organizations. He is the authors of an excess of 120 publications and technical reports. He has taught several mini workshops and has delivered more than 200 speeches. He is the recipient of several awards, honors, and scholarships both at the national and international level. He has served as session chair/co-chair and as selection committee member for International conferences and workshops.
TIME Friday, February 28, 2020 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering
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Feb28
EVENT DETAILS
lessTrouble Ahead, Trouble Behind: Acid Mine Drainage and Climate Change in the Rocky Mountains
Abstract
In the Rocky Mountain watersheds, weathering of disseminated pyrite in the country rock and in mining workings generates acidic, metal-enriched water that drains into streams and rivers. This overall process is referred to as acid rock drainage (ARD). ARD is a long-term and pervasive environmental problem in the Rocky Mountains and the Sierras, which provide water supply for communities and agriculture throughout the south western US. Contamination has not abated since the mining boom ended about 70 years ago, largely because these contaminants are continuously generated from the exposure to oxygen of pyrite in the mine workings and tailings. Typically these streams have high dissolved concentrations of toxic metals, such as Zn, Cu, Cd and Pb, and their streambeds are covered with iron and aluminum oxides. These streams and rivers support species-poor aquatic ecosystems, and fish are typically absent. A study in an ARD stream system that drains into Dillon Reservoir, a water supply for Denver, Colorado, has found that acidity and concentrations of metals and rare earth elements have been steadily increasing in the summer and fall over the past several decades. Another trend is that mountain resorts have been pursuing a “four seasons resort” approach to adapt to changing climate, and less reliable winter snowpack for skiing. ARD thwarts these plans by constraining the use of stream water for snowmaking and impacting summer recreation, such as fishing and rafting. In addition to general environmental concerns, this situation has focused attention on remediation of abandoned mines which is inherently challenging, as illustrated by the difficulties in remediating the Gold King Mine near Durango, CO. One issue for state and federal agencies and watershed stakeholders’ groups is determining which of the many abandoned mines in a catchment are the main ARD sources, and which of these are suitable for remediation. Addressing the ARD problem in mountain catchments will require a convergent research approach that integrates understanding of hydrology, water quality and aquatic ecosystem processes within a regulatory and water resources framework.Bio
Diane M. McKnight is a Professor in the Department of Civil, Environmental and Architectural Engineering, a member of the Environmental Engineering program faculty and a Fellow of the Institute of Arctic and Alpine Research at the University of Colorado. Her research focuses on the coupling of hydrology and water quality in streams and lakes, and the consequences for aquatic ecosystems and water supplies. She began her career as a research hydrologist with the U.S. Geological Survey, studying the biogeochemistry of lakes in the blast zone of Mt. St. Helens and acid mine drainage streams and pristine alpine lakes in the Rocky Mountains. She participated in designing ecological aspects of the National Water Quality Assessment Program of the USGS. Since 1992, she has conducted research on stream ecosystems as part of the McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) project in Antarctica. She has been President of the American Society of Limnology and Oceanography and editor of Journal of Geophysical Research-Biogeosciences. She served as the Chair of the Editorial Committee for the LTER Schoolyard Children’s Book Series and authored the second book in the series. She is a fellow of the American Geophysical Union, a member of the National Academy of Engineering and received the John Dalton Award from the European Geophysical Union in 2015.TIME Friday, February 28, 2020 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering
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Mar4
EVENT DETAILS
lessWhen Topology Met Phononics: Wave Manipulation on Edges and Interfaces
Abstract:
Elastic metamaterials are structural materials that owe their unique wave manipulation capabilities to their complex internal architecture. Topological metamaterials are special metamaterials whose behavior is directly controlled by the topology of their phonon band structure. In this talk, we present two problems in topological phononics that deal with the propagation of waves at edges and interfaces.The first problem regards a class of metamaterials known as topological Maxwell lattices. While this class of systems has been the object of extensive theoretical investigation, the classical treatment has been limited to ideal configurations and confined to the static limit. Here, we explore the dynamics of lattices in which the ideal hinges that appear in the theoretical models are replaced by ligaments capable of supporting bending deformation – a scenario practically observed in structures realized using cutting or printing fabrication techniques. Using laser vibrometry experiments, we reveal how the zero-energy floppy edge modes predicted for ideal configurations morph into finite-frequency wave modes that localize at the material boundaries. We also show that the topological polarization results in pronounced asymmetric wave transport over a broad low-frequency range.
In the second part of the presentation, we demonstrate the existence of valley-Hall edge states in the in-plane dynamics of honeycomb lattices with bi-valued strut thickness. We exploit these states to achieve non-trivial waveguiding that is immune to backscattering from sharp corners. We present how different types of interfaces can be combined into multi-branch junctions to realize a variety of structural logic designs. We illustrate this potential with two applications. The first is a direction-selective waveguide tree that endows the lattice with a strong asymmetric wave transport behavior. The second is an internal loop along which the energy can be periodically trapped and released, effectively working as a signal delayer.
Bio
Stefano Gonella received Ph.D. and M.S. in aerospace engineering from the Georgia Institute of Technology in 2007 and 2005, respectively, following a Laurea, also in aerospace engineering, from Politecnico di Torino (Italy) in 2003. He joined the faculty of the Department of Civil, Environmental and Geo- Engineering at the University of Minnesota in 2010, after 3 years of post-doctoral experience at Northwestern University. His research interests revolve around the modeling, simulation and experimental characterization of wave phenomena in architected materials, phononic crystals, and acoustic metamaterials. His latest efforts have been directed towards understanding the role of topological states of matter in the design of mechanical metamaterials and their implications for wave control. Stefano Gonella was recipient of the NSF CAREER award in 2015.TIME Wednesday, March 4, 2020 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering
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Mar13
EVENT DETAILS
lessLinking Dissolved Organic Matter Composition with Photoreactivity Using High-Resolution Mass Spectrometry
Abstract
The composition of dissolved organic matter (DOM) determines its photochemical reactivity and ability to form photochemically produced reactive intermediates (PPRI). We collected water samples in the St. Louis River in the United States, which includes of variety of DOM sources and processing. Bulk characterization techniques, such as measurements of total organic carbon and ultraviolet-visible spectroscopy, show the quantity of DOM, apparent molecular weight, and aromaticity all decrease downstream in the system. Characterization at the molecular level using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) reveals that saturation of DOM generally increases downstream. Photochemical experiments measuring quantum yields for PPRI formation show that upstream samples are more efficient at producing hydroxyl radical (•OH), while downstream samples are more efficient at producing triplet DOM (3DOM) and singlet oxygen (1O2). Spearman rank correlations were used to correlate formula intensities, as determined by FT-ICR MS, to observed quantum yields for PPRI formation and to photodegradation rate constants of target contaminants (atorvastatin, carbamazepine, DEET, and venlafaxine). These analyses indicate that the more saturated DOM pool most strongly correlated to formation of 3DOM and 1O2 is the same pool of DOM correlated to photodegradation of atorvastatin, carbamazepine, and venlafaxine. In contrast, highly aromatic DOM formulas are strongly correlated to •OH formation and DEET photodegradation. Together, these results demonstrate how DOM composition affects photoreactivity and contaminant fate.
Bio
Associate Professor Christy Remucal (née Christina Renée Keenan) leads the Aquatic Chemistry group at the University of Wisconsin-Madison and is the Director of the Water Science and Engineering Laboratory. She is a faculty member in the Department of Civil & Environmental Engineering, the Environmental Chemistry & Technology Program, and the Limnology & Marine Science Program. She holds an MS (2004) and a PhD (2009) in Civil & Environmental Engineering from the University of California, Berkeley, and a BS (2003) in Environmental Engineering Science from Massachusetts Institute of Technology. Before joining the UW-Madison faculty, Christy completed a post-doc in the Institute for Biogeochemistry and Pollutant Dynamics at the Swiss Federal Institute of Technology.
TIME Friday, March 13, 2020 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering
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Mar14
EVENT DETAILS
lessWinter Classes End
TIME Saturday, March 14, 2020
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
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Mar21
EVENT DETAILS
lessSpring Break Begins
TIME Saturday, March 21, 2020
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
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Mar30
EVENT DETAILS
lessSpring Break Ends
TIME Monday, March 30, 2020
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
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Mar31
EVENT DETAILS
lessSpring Classes begin 8 a.m.
Northwestern Monday: In the fall of 2019, President Schapiro and Provost Holloway announced changes to commencement, spring break and the start of the spring quarter: spring quarters will now routinely start on Tuesday, rather than Monday, to afford two full weekends of break.
Though spring quarters will begin on a Tuesday, the Monday class schedule will be in effect, a practice referred to as “Northwestern Monday.” Classes that usually meet only on Tuesdays will not meet during the first week of the term. This calendar applies to all quarter classes except those offered in the evening programs in the Kellogg School of Management and the School of Professional Studies (SPS).
TIME Tuesday, March 31, 2020
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
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Apr6
EVENT DETAILSmore info
lessThe Jan D. Achenbach Lecture
Presented by the Civil and Environmental Engineering and Mechanical Engineering Departments
Speaker:
Jennifer A. Lewis
Hansjörg Wyss Professor of Biologically Inspired Engineering
John A. Paulson School of Engineering and Applied Sciences & Wyss Institute
Harvard University
Abstract
3D printing enables one to rapidly design and fabricate materials in arbitrary shapes on demand. I will introduce the fundamental principles that underpin 3D printing methods pioneered by our group. I will then describe the design, composition, and rheological properties of functional, structural and biological inks that we have developed, which are vastly expanding the capabilities of 3D printing. Finally, I will highlight several examples from our recent work, including the fabrication and characterization of colloidal foams, shape-shifting architectures, and soft functional devices.
Biographical Sketch
Jennifer A. Lewis is the Jianming Yu Professor of Arts and Sciences, the Wyss Professor for Biologically Inspired Engineering in the Paulson School of Engineering and Applied Sciences, and a core faculty member of the Wyss Institute at Harvard University, where she co-leads the 3D Organ Engineering Initiative. Her research focuses on the directed assembly of functional, structural, and biological materials. She is a member of the National Academy of Sciences, National Academy of Engineering, National Academy of Inventors, and the American Academy of Arts and Sciences. She has received numerous awards, including the National Science Foundation Presidential Faculty Fellow Award, the American Chemical Society Langmuir Lecture Award, the Materials Research Society Medal Award, the American Ceramic Society Sosman Award, and the Lush Science Prize. Her work has enjoyed broad coverage in the popular media. To date, she has co-founded two companies that are commercializing technology from her lab.TIME Monday, April 6, 2020 at 3:00 PM - 4:00 PM
LOCATION L211, Technological Institute map it
CONTACT Tierney Acott tierney-acott@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering