Department Seminars: Spring 2011
Past Seminars
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"Sustainability Engineering Applied to the Evaluation Capacity of RC Members to Resist Man Made as well as Natural Hazards" Thursday, April 28, 2011, 12:00 – 12:45 PM, Hodson 311 US seismic codes and standards have significantly improved in the last three decades: however, significant business disruptions continue to occur due to severe damage of infrastructure. This constitutes a major portion of the total economic loss in the aftermath of any event. This has motivated researchers to move towards other design alternatives that can consider controllable damage design as well as structural safety. As a result, the future in structural engineering is leaning towards a performance-based design approach, which implies that engineered facilities should be designed with the broader needs of society in mind. Recently, terrorist attacks on non-military structures around the world have increased the level of research on blast loads and their effects on structures. Much of this research was devoted primarily to military applications against missiles with or without nuclear capabilities. Clearly, civil infrastructure designed to this level of protection would be considerably robust, and would not properly service the public sector in terms of aesthetics, and economic concerns. Consequently, design alternatives are needed that can be effectively implemented for the design of civil infrastructures to resist seismic as well as blast/impact loads. Although seismic and blast loads distress structures in different ways, the engineering profession would benefit considerably if engineers were to implement design procedures that could be implemented effectively for seismic as well as blast loads. |
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"The Baltimore Red Line Light Rail Project" Friday, April 29, 2011, 12:00 – 12:45 PM, Hodson 110 This presentation will focus on the current status of the Baltimore Red Line project, as well as provide a project overview, milestone steps and a schedule for implementation, capital cost estimate, key engineering considerations (civil, systems, traffic), third party coordination, station planning, tunnel considerations, public involvement, maintenance yard and shop requirements, and environmental stewardship. |
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"Spatial Structure Projects in China" Thursday, April 7, 2011, 12:00 – 12:45 PM, Hodson 311 Spatial structures have been widely applied in China in recent decades. Almost all stadiums and gymnasiums used in 2008 Beijing Olympics and many pavilions of 2010 Shanghai Expo were designed as spatial structures. Some particular spatial structure projects in China will be presented in this seminar. More than 100 pictures of Shanghai Expo pavilions are shown quickly first. Following three unique spatial structure projects, China National Stadium (‘Bird Nest’), Dalian International Conference Center and a large span air-supported & air-inflated combined fabric structure, are briefly introduced respectively. Some mechanical concepts and structural optimization methods are illuminated through some spatial structure projects. |
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"What is Engineering Ethics?" Friday, April 8, 2011, 12:00 – 12:45 PM, Hodson 110 This talk presents my idiosyncratic view about the development and status of the field of engineering ethics. I begin by mentioning a few of the controversies surrounding professional codes of ethics and provide a tiny bit of history about the civil engineering code of ethics. Then I try to describe and distinguish among fields of professional ethics. Next, I review a set of requirements or skills for addressing issues of science or engineering ethics. Finally, we will examine a case using these skills. In any time remaining, I will describe briefly several projects underway at CEES. |
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"The Whole Building Design Guide – the Online Tool to Achieve High-Performance Buildings" Friday, March 18, 2011, 12:00 – 12:45 PM, Hodson 110 To achieve high-performance buildings, there is a need for collaboration among project team members to attain success in the planning, design, construction and operations of buildings. In this talk, we will define what a high-performance building is; discuss why we aren't getting them now; and explain what it takes to achieve high performance. The integrated design process will be presented and we will explore the Whole Building Design Guide as an online tool to achieving high-performance. The audience for the presentation includes engineers, architects, project managers, educators, students, and other involved in the planning, design, construction and operation of buildings. |
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"Non-Equilibrium Deformations in Phase-Transforming Materials and Nanostructures" Thursday, March 17, 2011, 12:00 – 12:45 PM, Hodson 311 Two studies of non-equilibrium behavior in complex materials will be presented. First, an application of the recent mesoscale peridynamic theory of continuum mechanics to the dynamic propagation of a martensitic phase boundary. Peridynamics is a continuum formulation that works directly with the displacement field, providing some freedom from tracking discontinuities, as well as incorporating long-range effects that can be important at small scales. Our study of martensitic interfaces in the peridynamic framework suggests that the theory is closed with respect to kinetics and nucleation and does not require additional information as in classical continuum mechanics. Second, the use of the method of Objective Structures to the non-equilibrium deformation and failure of carbon nanotubes at imposed strain rates of 104/s - 108/s. Objective Structures generalizes the notion of crystallinity to important non-crystalline nanostructures such as carbon nanotubes. This allows the calculation of properties of these nanostructures through efficient techniques developed for crystals. dynamics in settings far from equilibrium. |
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"Geometric Mechanics of Growing Bodies" Thursday, March 10, 2011, 12:00 – 12:45 PM, Hodson 311 In this seminar we present some applications of differential geometry in solid mechanics. Traditionally, mechanics has been formulated in Euclidean spaces, mainly for convenience and simplicity. In the early days of modern solid mechanics engineering scientists were interested in the simplest possible models. Working with these models for the practical problems of the time laid the foundations of continuum mechanics. However, from experience in physics we know that, in general, configuration space of a physical system is not globally Euclidean; physical theories should be formulated on manifolds. We first motivate the recent geometric studies in continuum and discrete mechanics by some important applications of geometric ideas, e.g. systematic discritizations of elasticity, mechanics of distributed defects, and mechanics of growing bodies. We then discuss a geometric formulation of bulk growth. Bulk growth is modeled by a material manifold with an evolving metric. In this theory time dependence of metric represents the evolution of the stress-free (natural) configuration of the body in response to changes in mass density. We show that time dependency of material metric will affect all the governing equations. We make an explicit connection between this geometric theory and the conventional multiplicative decomposition of deformation gradient F = FeFg into growth and elastic parts. We will also comment on the linearized theory. |
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"A new approach to wind energy" Friday, March 4, 2011, 12:00 – 12:45 PM, Hodson 110 Modern wind farms require significant land resources to separate each wind turbine from the adjacent turbine wakes. This aerodynamic constraint limits the amount of power that can be extracted from a given wind farm footprint. We investigated the use of counter-rotating vertical-axis wind turbines in order to achieve higher power output per unit land area than existing wind farms consisting of propeller-style turbines. Full-scale field tests of vertical-axis wind turbines in various counter-rotating configurations were conducted under natural wind conditions during summer 2010. Whereas wind farms consisting of propeller-style turbines produce 2 to 3 watts of power per square meter of land area, these field tests indicate that power densities an order of magnitude greater can be achieved by arranging vertical-axis wind turbines in layouts that enable them to extract energy from adjacent wakes and from above the wind farm. Moreover, this improved performance does not require higher individual wind turbine efficiency, only closer wind turbine spacing and a sufficient vertical flux of turbulence kinetic energy from the atmospheric surface layer. The results suggest an alternative approach to wind farming that has the potential to concurrently reduce the cost, size, and environmental impacts of wind farms. |
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"Design and Construction of High Soil Berms Over Soft Soils Using a Hybrid Drained-Undrained (HDU) Model" Friday, February 24, 2011, 12:00 – 12:45 PM, Hodson 311 In July 2010, the construction of an 8,000-ft long, 70-ft high mechanically stabilized earth (MSE) berm was completed at the Cherry Island Landfill site, which is owned by the Delaware Solid Waste Authority. The completion of this two-million yd3 MSE berm represents a significant engineering achievement considering the size of the embankment and the deep layer of very soft soils under the berm. A novel design methodology, the Hybrid Drained-Undrained (HDU) Model, was used to analyze the strength characteristics of the soft foundation soils during construction. The United States Corps of Engineers used the site as a dredge disposal site. The dredge and the underlying alluvium deposit form a 60-100-ft thick foundation of extremely weak and low-permeability soils having undrained shear strengths as low as 200 pounds per square foot (psf). In this seminar, the geometric and loading constrains used in the design of the landfill expansion will be explored. In addition, the main challenges involved in landfill design, in particular involving vertical expansion over soft clays, will be discussed. Numerical analysis using Finite Element Method models used during the design stage of the landfill expansion, predictions of settlement and horizontal deformation, and analysis used during the erection of the wall to determine a safe rate of soil placement will be presented. |
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"Geospatially Enabling Civil Engineering" Thursday, February 17, 2011, 12:00 – 12:45 PM, Hodson 311 With the maturing of GIS and geospatial information, bringing the power of geospatially-referenced information to the problems and decisions of today is critical. Geospatial information, technology, and analysis are integrated into and across an increasing number of fields and professions including Civil Engineering. The integration, interpretation, use, and limitations of geospatial information as it is transformed into knowledge for decision making is an important and evolving necessity in today's geospatially aware environment. Geospatial technologies provide a transformational capability to integrate information across disciplines and domains using location as the integrator. A critical method for integrating hard and soft science topologies is through location or geospatial space. |
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"Challenges of Geotechnical Engineering: the construction of a high soil berm over very soft soils" Friday, February 11, 2011, 12:00 – 12:45 PM, Hodson 110 In July 2010, after four years, construction of an 8,000-ft long, 70-ft high mechanically stabilized earth (MSE) berm was completed at the Cherry Island Landfill site, which is owned by the Delaware Solid Waste Authority. The completion of this two-million-cubic-yard MSE berm represents a significant engineering achievement considering the size of the embankment and the deep layer of very soft soils over which the berm was constructed. A central element of the design was the use of a novel design methodology, the Hybrid Drained-Undrained (HDU) Model, to analyze the strength characteristics of the soft foundation soils during construction. The site, which is located at the confluence of the Delaware and Christina Rivers, was partly reclaimed from the Delaware River in the early 1900’s and used as a dredge disposal site by the United States Corps of Engineers. The dredge and the underlying alluvium deposit form a 60- to 100-ft thick foundation of extremely weak and low-permeability soils having undrained shear strengths as low as 200 pounds per square foot (psf). In this seminar, the reasons why sometimes engineers site critical projects over soft, non-competent soils will be explored. In addition, the main challenges involved in landfill design, in particular involving vertical expansion over soft clays, will be discussed. An overview of the numerical formulation used during the design stage of the landfill expansion will be presented. |
Seminar Archives
Past Seminars: Spring 2011
Past Seminars: Fall 2010
Past Seminars: Spring 2010
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Past Seminars: Spring 2009
Past Seminars: Fall 2008
Past Seminars: Before Fall 2008