Active and Past Projects
National Science Foundation (Rice). CAREER: Loading on Coastal Bridges in Windstorms Using Rapidly Deployable Sensor Network. May 1, 2015 – April 30, 2020. This Faculty Early Career Development (CAREER) Program grant seeks to transform coastal bridge resilience through cyberinfrastructure supported extreme event observations. The damaging effects of severe windstorms including hurricanes on infrastructure of coastal bridges highlight the need for new tools to provide fundamental knowledge of windstorm impacts on infrastructure. This award supports fundamental research to establish a rapidly deployable, bridge-located observation network to lay the groundwork for capturing measurements of wind, surge, wave, and scour and analysis of bridge responses during a severe storm such as a hurricane. These efforts will enhance coastal bridge health management decisions as well as design and reliability models through the analysis of hurricane load and response data. A full-scale prototype of this system deployed on a bridge with interactive system will provide students at all academic levels the opportunity to interact with an in-service bridge and visualize the impacts of bridge management decisions.The rapidly deployable bridge-hurricane observation network will advance fundamental knowledge of the loadings and responses of bridges in coastal storms. The introduction of wireless smart sensor networks has promise of transforming bridge management; however, their potential has been restricted by static application software that is unable to respond to changing monitoring conditions. Under this CAREER program, a cyberinfrastructure enabled dynamically reconfigurable smart sensor framework will be created based on mobile agents. These are the software programs that traverse the wireless sensor network and act intelligently to facilitate network and sensor functionality in response to changes in the bridge loading and response. To realize the full benefits of the bridge monitoring framework, there should be a link between the data it produces and effective bridge management decisions. This link will be pursued by coupling extreme event data with advanced bridge response and windstorm phenomena simulation tools to enable the development of accurate coastal bridge reliability models.
National Science Foundation. MRI: Develop Instrumentation to Advance Fundamental Research on Simulating Complex Wind Flow Near the Earth’s Surface. September 1, 2014 – August 31, 2017. The boundary layer wind tunnel is an essential research tool for creating dynamic wind flow that replicates the natural behavior of wind near the Earth?s surface. This wind flow is applied to models of buildings and other structures to determine their expected performance and to design them to survive extreme wind events. The accurate replication of natural wind in a laboratory is not trivial. The methods and equipment vary depending upon the wind condition (tornadoes, hurricanes, thunderstorms, etc.), and the geographic location of the object being studied (near the coast, in a suburban community, etc.). Current wind tunnel facilities are limited in this regard, each capable of addressing a small subset of wind phenomena. This award supports the development of an instrument that vastly expands the capability of a single facility to study a wide range of wind conditions observed in nature and assess how they affect the built and natural environments. This capability will accelerate the rate of discovery and open pathways to solving problems in the development of resilient infrastructure. Other applications include the study of pollutant dispersion, siting of wind energy resources, biomechanics, human perception of hazards, and micro aerial vehicle development. The project includes participants from five continents. Thus the development of this instrument will strengthen US competitiveness by enabling a breakthrough in boundary layer wind tunnel technology, while enhancing international collaboration on wind hazard issues that impact the entire populated world. The objective is to develop an instrument capable of simulating nonstationary, non-neutral or transitioning surface flows. Examples include offshore hurricane winds flowing into a terrestrial environment, non-stationary gust fronts in thunderstorms, transient coherent structures induced by the shearing motion aloft and wind-driven rain. The instrument will command static and dynamic control devices that automatically reconfigure to achieve user-specified similarity requirements such as non-monotonic profiles, spatially variable power spectra and integral length scales, transient gusts, and rain entrainment in the flow field. These control devices must work in series (one stage conditions the next) to achieve the intended function of the instrument. The instrument includes components adapted from existing proof-of-concept studies and new technology to be developed. The framework on which the instrument is to be developed is a conventional boundary layer wind tunnel design, as a goal is to create a tool suitable for implementation in facilities worldwide.
National Science Foundation (Prevatt). CAREER: Tornado-Resilient Structural Retrofits for Sustainable Housing Communities. March 1, 2013 – February 28, 2017. The objectives of this Faculty Early Career Development (CAREER) program award are to characterize tornadic wind loads on a residential building and to compare the resultant structural response of traditional construction against a structurally enhanced one. Study variables include both tornado parameters (vortex size, forward speed, pressure profile and swirl ratio), and the building parameters (building location relative to the tornado core, structural connections, and the main wind force resisting system). A 3-dimensional Finite Element Analysis model of a light-framed residential structural system will be used as the prototype to establish structural response. A database-assisted design (DAD) methodology will be used to analyze tornadic wind load time-histories from a model building shape and determine critical design loads and reactions for the structural system. Full-scale tests will be conducted on corner substructures of the prototype building for validating the numerical model and also to evaluate the structural and economic benefits of enhanced structural systems in houses. The effort will provide the basis for a tornado-resilient design methodology for houses. The award facilitates knowledge generation that provides a better understanding of the structural behaviors and vulnerability of existing wood-framed houses, while identifying benefits to a community that incorporate tornado-resilient building structural systems. A new graduate-level course, Engineered Design of Sustainable Residential Structures will provide knowledge to civil engineering graduate students, and enable them to interact with residential building contractors, and structural engineers. Information on tornadic loads and structural enhancement of houses will be made available to builders via webbased portals. A Wind Hazard Damage Assessment Group will be formed to conduct post-storm assessments and to disseminate research findings on advanced residential construction practices. Through research immersion, K-12 science teachers will develop high-school teaching modules on tornado damage to houses for inclusion in high-school science curricula. Training and mentorship of a PhD student will be provided in experimental and analytical studies. This award will provide resources that will be used to develop technologies to improve performance of low-rise buildings affected by tornadoes.
National Science Foundation (Masters). CAREER: Behavior of Hurricane Wind and Wind-Driven Rain in the Coastal Suburban Roughness Sublayer. March 1, 2011 – February 28, 2016. The research objective of this Faculty Early Career Development (CAREER) program project is to define the tropical cyclone surface wind field, wind-driven rain characteristics and wind loading in the built environment. The goal is to determine how localized, coherent features occurring in the rough-wall turbulent boundary layer and larger-scale convective features (such as meso-vortices, rainband core downdrafts) influence the surface wind field characteristics and loading on low-rise structures. The project will utilize the instrumented towers managed by Florida Coastal Monitoring Program. The towers will be retrofitted to collect turbulence and wind-driven profile measurements and will be deployed in coastal suburban communities where the most damaging winds are expected to occur. These observational towers will be located inside mobile Doppler radar networks that are deployed by the Digital Hurricane Consortium to determine if convective features aloft modulate the ground level wind structure. The wind field data will be coupled with pressure measurements on single-family homes to directly relate the peak load conditions to the full spectrum of the wind effects. The project addresses the important issue of the interaction of hurricane induced winds with engineered structures. The project will provide important data for wind tunnel and computational modeling, evaluation of the existing provisions in building codes and standards, cost effective damage mitigation measures, and resilient design of structures. The project will also strengthen interactions between the wind engineering and atmospheric science disciplines. The project will provide advanced training to graduate and undergraduate students through their direct involvement in the project work. Middle school teachers from under-resourced schools located in hurricane-prone areas will participate in a pilot initiative called the Hurricane Hazard Immersion Program. This program is expected to enhance the 6-8th grade curriculum of over 7500 students living along the hurricane prone coast through annual training and active participation of 25 middle school teachers in the project research. The program is designed to be sustainable beyond the project duration; it will target underrepresented groups and foster a culture of hazard preparedness and proactive mitigation among the next generation of homeowners.
National Science Foundation (Gurley). CAREER: Modeling and Simulation of Wind Loads for Wind Hazard Mitigation. May 15, 2000 – May 14, 2005. The research offers advancements in the accurate representation of natural hazard loads for application in structural reliability assessment. The focus is on the modeling and simulation of highly correlated non-Gaussian extreme wind loads on building components. Modeling efforts will focus on the probability content, spatial and temporal coherence, integral effects over large areas, transient, and higher-order phenomena associated with extreme wind forces in the building envelope. Robust simulation methods will adopt these models, and provide a consistent frame-work for applications in reliability analysis. This will enhance the impact of reliability methods on hazard resistant design through a more realistic treatment of severe loading. Concurrent efforts in full-scale hurricane wind measurement near ground level will provide necessary data to advance this research. The educational goals are to produce engineers prepared to design against natural hazards, and to provide a medium for graduate work in this emerging field.