Global ETD Search

61	Aerodynamic Load Characteristics Evaluation and Tri-Axial Performance Testing on Fiber Reinforced Polymer Connections and Metal Fasteners to Promote Hurricane Damage Mitigation Canino-Vazquez, Iván R. 13 November 2009 (has links) Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests, sets of three force components (tri-axial mean loads) were combined into a series of resultant mean forces, which were used to test the FRP and metal connections in the structures laboratory up to failure. A new component testing system and test protocol were developed for testing fasteners under simulated tri-axial loading as opposed to uni-axial loading. The tri-axial and uni-axial test results were compared for hurricane clips. Also, comparison was made between tri-axial load capacity of FRP and metal connections. The research findings demonstrate that the FRP connection is a viable option for use in timber roof-to-wall connection system. Findings also confirm that current testing methods of mechanical fasteners tend to overestimate the actual load capacities of a connector. Additionally, the research also contributes to the development a new testing protocol for fasteners using tri-axial simultaneous loads based on the aerodynamic database obtained from the WoW testing. Roof-to-Wall Connections Timber Connections Fiber Reinforced Polymers Tri-Axial Performance Testing Hurricane Simulation Hurricane Clips Hurricane Damage Mitigation Tropical Cyclone Simulation Continuous Load Path
62	Finite Element Modeling for Assessing Flood Barrier Risks and Failures due to Storm Surges and Waves Wood, Dylan M. January 2020 (has links) No description available. Civil Engineering Environmental Engineering Fluid Dynamics Geotechnology Meteorology Ocean Engineering Finite element computational fluid dynamics hydrodynamics shallow water parametric wind spectral wave storm surge hurricane tropical cyclone levee barrier discontinuous Galerkin numerical quadrature Runge-Kutta overtopping piping flood
63	Analysis of storm surge impacts on transportation systems in the Georgia coastal area Restrepo, Ana Catalina 18 November 2011 (has links) Many Climate Scientists believe that global warming will produce more extreme weather events such as tropical storms, hurricanes, intense rainfall, and flooding. These events are considered to be the most catastrophic natural events for transportation systems especially in coastal areas. Due to the severe damage from storm surge and flooding. Evaluating the magnitude of possible storm surges and their impacts on transportation systems in coastal areas is fundamental to developing adaptation plans and impact assessments to mitigate the damage. This thesis focuses on existing transportation systems in the Georgia coastal area that could be affected by several storm surges. An existing storm surge model is used to estimate the storm surges and the surge heights based on the category, direction, and forward speed of a storm. The ground elevation of the ports, interstates, state roads, railroads, and the principal airports on the Georgia coast are identified through a GIS analysis using the national elevation data set. Having the storm surge elevation and the elevation of the existing infrastructure, a GIS study is performed to identify those parts of the transportation system that will be affected by each type of storm giving results such as the length or sections of transportation assets under or above the surge elevation. A literature review of storm surge, rising sea levels, and their impacts on coastal bridges, roads, airports, ports, and railroads is presented in the thesis. Also, a description of the software used to analyze and estimate the impacts of climate change on transportation systems is described. Raster files Maximum surge elevation Storm direction Ground elevation Scour Wave forces Forward speed average surge elevation Transportation systems Railroads Interstate roads Roads Georgia coast Storm surge Transportation assets Transportation impacts Hurricane category Inundation Landfall Tropical cyclone Transportation maps Counties along the Georgia coast Geographic information system Vector files Storm surge model Hypothetical storm Airports Ports Bridges Hurricane Global warming Storm surges Floods
64	The Simulation & Evaluation of Surge Hazard Using a Response Surface Method in the New York Bight Bredesen, Michael H 01 January 2015 (has links) Atmospheric features, such as tropical cyclones, act as a driving mechanism for many of the major hazards affecting coastal areas around the world. Accurate and efficient quantification of tropical cyclone surge hazard is essential to the development of resilient coastal communities, particularly given continued sea level trend concerns. Recent major tropical cyclones that have impacted the northeastern portion of the United States have resulted in devastating flooding in New York City, the most densely populated city in the US. As a part of national effort to re-evaluate coastal inundation hazards, the Federal Emergency Management Agency used the Joint Probability Method to re-evaluate surge hazard probabilities for Flood Insurance Rate Maps in the New York – New Jersey coastal areas, also termed the New York Bight. As originally developed, this method required many combinations of storm parameters to statistically characterize the local climatology for numerical model simulation. Even though high-performance computing efficiency has vastly improved in recent years, researchers have utilized different “Optimal Sampling” techniques to reduce the number of storm simulations needed in the traditional Joint Probability Method. This manuscript presents results from the simulation of over 350 synthetic tropical cyclones designed to produce significant surge in the New York Bight using the hydrodynamic Advanced Circulation numerical model, bypassing the need for Optimal Sampling schemes. This data set allowed for a careful assessment of joint probability distributions utilized for this area and the impacts of current assumptions used in deriving new flood-risk maps for the New York City area. Thesis University of North Florida UNF Natural Hazards Storm Surge Tropical Cyclone Joint Probability Method Annual Exceedance Probability New York Bight Civil Engineering Climate Earth Sciences Meteorology Numerical Analysis and Computation Ocean Engineering Oceanography Other Engineering Other Mathematics Other Statistics and Probability Probability Risk Analysis Statistical Models Statistics and Probability Sustainability

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