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- Title
- Berth scheduling in container terminals: a pro-active approach to address uncertainties in arrival and handling times.
- Creator
- Portal Palomo, Maria I., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Ports and container terminals have very complex and dynamic operations. Effective and efficient berth schedules are essential for profitable and sustainable operations. This research studies berth scheduling under uncertainties in arrival and handling times. Port operators usually face challenges in the development of berth schedules. This thesis presents a model formulation of discrete berth space that accounts for uncertainty in arrival and handling times. The problem is reformulated as a...
Show morePorts and container terminals have very complex and dynamic operations. Effective and efficient berth schedules are essential for profitable and sustainable operations. This research studies berth scheduling under uncertainties in arrival and handling times. Port operators usually face challenges in the development of berth schedules. This thesis presents a model formulation of discrete berth space that accounts for uncertainty in arrival and handling times. The problem is reformulated as a biobjective bi-level optimization berth scheduling problem. A solution approach is presented using evolutionary algorithms and heuristics. The objective of the formulation is to provide a robust berth schedule by minimizing the average and the range of the total service times for all vessels served at the terminal. Simulation is utilized to evaluate the proposed berth scheduling policy and compare it to two first-come-first-served policies. Results showed that the proposed berth schedules outperform under high congestion.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3360960
- Subject Headings
- Container terminals, Management, Marine terminals, Management, Transportation, Planning, Freight and freightage
- Format
- Document (PDF)
- Title
- Analysis of ship hull and plate vibrations caused by wave forces.
- Creator
- Lakitosh, Fnu, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In the present dissertation, the hydrodynamic and hydro-elastic characteristics of ship hull and plate vibrations are analyzed using theoretical and numerical methods. The wave forces are determined using a suite of methods which include the Froude-Krylov method for incident wave forces, Wagner's method and ABS rules for the slamming wave force, and numerical methods for nonlinear wave radiation forces. Finite difference methods are developed to determine the wave forced vibrations of ship...
Show moreIn the present dissertation, the hydrodynamic and hydro-elastic characteristics of ship hull and plate vibrations are analyzed using theoretical and numerical methods. The wave forces are determined using a suite of methods which include the Froude-Krylov method for incident wave forces, Wagner's method and ABS rules for the slamming wave force, and numerical methods for nonlinear wave radiation forces. Finite difference methods are developed to determine the wave forced vibrations of ship hull plates which are modeled using a range of plate theories including nonlinear plate theory with and without material damping and orthotropic plate theory for stiffened hull plates. For small amplitude deformation of thin plates, a semi-theoretical superposition method is used to determine the free and forced vibrations. The transient ship hull vibration due to whipping is also analyzed using the finite difference method. Results, in the form of deformations and stress distributions, are obtained for a range of scantling and wave parameters to identify key parameters to consider in ship structural design.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342196
- Subject Headings
- Vibration (Marine engineering), Hulls (Naval architecture), Ships, Hydraulic impact, Ocean waves, Mathematical models, Fluid dynamics, Mathematical models
- Format
- Document (PDF)
- Title
- Boundary reflection coefficient estimation from depth dependence of the acoustic Green's function.
- Creator
- Conrad, Alexander., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Sound propagation in a waveguide is greatly dependent on the acoustic properties of the boundaries. The effect of these properties can be described by a bottom reflection coefficient RB, and surface reflection coefficient RS. Two methods for estimating reflection coefficients are used in this research. The first, the ratio method, is based on the variations of the Green's function with depth utilizing the ratio of the wavenumber spectra at two depths. The second, the pole method, is based on...
Show moreSound propagation in a waveguide is greatly dependent on the acoustic properties of the boundaries. The effect of these properties can be described by a bottom reflection coefficient RB, and surface reflection coefficient RS. Two methods for estimating reflection coefficients are used in this research. The first, the ratio method, is based on the variations of the Green's function with depth utilizing the ratio of the wavenumber spectra at two depths. The second, the pole method, is based on the wavenumbers of the modal peaks in the spectrum at a particular depth. A method to invert for sound speed and density is also examined. Estimates of RB and RS based on synthetic data by the ratio method were very close to their predicted values, especially for higher frequencies and longer apertures. The pole method returned less precise estimates though with longer apertures, the estimates were better. Using experimental data, results of the pole method as well a geoacoustic inversion technique based on them were mixed. The ratio method was used to estimate RS based on the actual data and returned results close to the predicted phase of p.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/3164094
- Subject Headings
- Underwater acoustics, Acoustic surface waves, Green's functions, Electromagnetic waves, Mathematics, Wave equation, Numerical solutions
- Format
- Document (PDF)
- Title
- Characterizing magnetic noise of AUV for use in towed magnetometer study of internal waves.
- Creator
- Tilley, Dylan., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
As part of a project to study internal waves, FAU plans to utilize an AUV to tow a magnetometer to study electromagnetic signatures from internal waves. This research is focused on the electromagnetic noise issues related to using an AUV to tow the magnetic sensor package. There are active sources of electromagnetic noise caused by an AUV that are present in addition to those induced by the Earth's magnetic field and permanent magnets. To characterize the magnetic noise associated with the...
Show moreAs part of a project to study internal waves, FAU plans to utilize an AUV to tow a magnetometer to study electromagnetic signatures from internal waves. This research is focused on the electromagnetic noise issues related to using an AUV to tow the magnetic sensor package. There are active sources of electromagnetic noise caused by an AUV that are present in addition to those induced by the Earth's magnetic field and permanent magnets. To characterize the magnetic noise associated with the AUV magnetometer tow system, the various active source elements were identified, the orientation sensitivity of the sensors being used was determined, and the magnetic anomaly of a similar AUV which may be eventually be used in a magnetic sensing arrangement was measured. The results are used to show the proposed sensing arrangement will likely not achieve the necessary sensitivity to measure subtle internal wave signals.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352881
- Subject Headings
- Automatic control, Mathematical models, Electromagnetic measurements, Fluctuations (Physics), Oceanographic submersibles, Underwater acoustics
- Format
- Document (PDF)
- Title
- Carbon fiber/vinylester composites in the marine environment: EIS as a means of determining an effective composite interface.
- Creator
- Vinci, Chris J., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In this research, the degradation of carbon fiber/vinylester composites in marine environments was experimentally investigated. Additionally, two types of carbon fiber surface treatments, namely Polyhedral Oligomeric Silsesquioxane (POSS) and the industrial surface treatment F0E, were evaluated to determine their effectiveness in creating a fiber/matrix (F/M) interface for use in the marine environment. Electrochemical Impedance Spectroscopy (EIS) was explored as a new application of an...
Show moreIn this research, the degradation of carbon fiber/vinylester composites in marine environments was experimentally investigated. Additionally, two types of carbon fiber surface treatments, namely Polyhedral Oligomeric Silsesquioxane (POSS) and the industrial surface treatment F0E, were evaluated to determine their effectiveness in creating a fiber/matrix (F/M) interface for use in the marine environment. Electrochemical Impedance Spectroscopy (EIS) was explored as a new application of an existing technique for use in measuring the amount of water at the F/M interface in carbon fiber/vinylester composites. EIS spectra were used to determine equivalent electric circuit models that allow for the prediction of water at the interface. The location of water within the composite was determined through Positron Annihilation Lifetime Spectroscopy (PALS). Interlaminar shear strength and transverse tensile tests were carried out for dry conditions and after hygrothermal exposure of the composites to study the influence of the integrity of the F/M interface on the macroscopic response of the composite.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1930500
- Subject Headings
- Composite materials, Mechanical properties, Graphite fibers, Fibrous composites, Structural analysis
- Format
- Document (PDF)
- Title
- Coating selection process for Gulf Stream hydroturbines.
- Creator
- Bak, Andrew Spicer., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The study addresses the coating selection for a proposed placement of a hydroturbine into the Gulf Stream. The turbine will generate energy in a similar manner to a wind turbine. The effects of biofouling and corrosion in the current project are assessed. A review of different types of traditional paint coatings is given, as well as the option for a copper-nickel alloy. Testing that should be undertaken for the coating selection is described in detail. Coating considerations are offered and...
Show moreThe study addresses the coating selection for a proposed placement of a hydroturbine into the Gulf Stream. The turbine will generate energy in a similar manner to a wind turbine. The effects of biofouling and corrosion in the current project are assessed. A review of different types of traditional paint coatings is given, as well as the option for a copper-nickel alloy. Testing that should be undertaken for the coating selection is described in detail. Coating considerations are offered and discussed. Design considerations and modifications are also offered.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/368607
- Subject Headings
- Hydraulic turbines, Materials, Testing, Coatings, Thermal properties, Protective coatings
- Format
- Document (PDF)
- Title
- Concrete diffusivity and its correlation with chloride deposition rate on concrete exposed to marine environments.
- Creator
- Echevarria, Victor Anthony., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per...
Show moreThe aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per square meter of exposed area could be found within the concrete samples. After 6 months, slag G1a blocks showed the most resistance to chloride penetration in the tidal and splash simulations. After 10 months of exposure, fly ash samples had the slowest rates of diffusion in the tidal simulation while the fly ash + silica fume samples and the slag samples measured similar rates of diffusion within the tidal zone. After 90 days of curing, cylinders composed of 20% fly ash & 8% silica fume measured the highest average resistivity values and were found to be less vulnerable to chloride ion penetration than the 20% fly ash and the 50% slag concrete through rapid migration tests.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358557
- Subject Headings
- Reinforced concrete, Construction, Corrosion, Composite reinforced concrete, Corrosion, Testing, Concrete, Fluid dynamics, Concrete, Chemical resistance, Chlorides, Diffusion rate
- Format
- Document (PDF)
- Title
- Degradation of mechanical properties of vinylester and carbon fiber/vinylester composites due to environmental exposure.
- Creator
- Figliolini, Alexander M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
An experimental investigation was undertaken to determine the effects of marine environmental exposure on the mechanical properties of vinylester resins (VE510A and VE8084) and carbon fiber/VE510A vinylester composites. The effect of carbon fiber sizing on the composite strengths was also examined. Neat resins were exposed to marine environments until moisture content reached a point of saturation after which they were tested in tension, compression and shear. Compared to the baseline dry...
Show moreAn experimental investigation was undertaken to determine the effects of marine environmental exposure on the mechanical properties of vinylester resins (VE510A and VE8084) and carbon fiber/VE510A vinylester composites. The effect of carbon fiber sizing on the composite strengths was also examined. Neat resins were exposed to marine environments until moisture content reached a point of saturation after which they were tested in tension, compression and shear. Compared to the baseline dry specimens, specimens subjected to moisture showed overall increased ductility and a reduction in strength. Dry and moisture saturated composite specimens were tested in tension and compression in different orientations. Longitudinal specimens were tested in in-plane shear and interlaminar shear. Composites with F-sized carbon fibers displayed overall higher strength than those with G-sized fibers at both dry and moisture saturated conditions. An analysis of moisture absorption of the composites was performed which vii shows that the moisture up-take is dominated by the fiber/matrix region which absorbs up to 90% of the moisture. The composites experienced reduced strength after moisture absorption. The results revealed that the fiber sizing has stronger effect on the fiber/matrix interface dominated strengths than moisture up-take.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3332182
- Subject Headings
- Composite materials, Mechanical properties, Polymers, Deterioration, FIbrous composites, Graphite fibers
- Format
- Document (PDF)
- Title
- Design and analysis of an ocean current turbine performance assessment system.
- Creator
- Young, Matthew T., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis proposes a sensor approach for quantifying the hydrodynamic performance of Ocean Current Turbines (OCT), and investigates the influence of sensor-specific noise and sampling rates on calculated turbine performance. Numerical models of the selected sensors are developed, and then utilized to add stochastic measurement error to numerically-generated, non-stochastic OCT data. Numerically-generated current velocity and turbine performance measurements are used to quantify the relative...
Show moreThis thesis proposes a sensor approach for quantifying the hydrodynamic performance of Ocean Current Turbines (OCT), and investigates the influence of sensor-specific noise and sampling rates on calculated turbine performance. Numerical models of the selected sensors are developed, and then utilized to add stochastic measurement error to numerically-generated, non-stochastic OCT data. Numerically-generated current velocity and turbine performance measurements are used to quantify the relative influence of sensor-specific error and sampling limitations on sensor measurements and calculated OCT performance results. The study shows that the addition of sensor error alters the variance and mean of OCT performance metric data by roughly 7.1% and 0.24%, respectively, for four evaluated operating conditions. It is shown that sensor error results in a mean, maximum and minimum performance metric to Signal to Noise Ration (SNR) of 48.6% and 6.2%, respectively.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359164
- Subject Headings
- Marine turbines, Mathematical models, Fluid dynamics, Structural dynamics, Stochastic processes, Rotors, Design and construction, Testing
- Format
- Document (PDF)
- Title
- Design & performance of a wind and solar-powered autonomous surface vehicle.
- Creator
- Rynne, Patrick Forde., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The primary objective of this research is the development a wind and solar-powered autonomous surface vehicle (WASP) for oceanographic measurements. This thesis presents the general design scheme, detailed aerodynamic and hydrodynamic aspects, sailing performance theory, and dynamic performance validation measurements obtained from a series of experiments. The WASP consists of a 4.2 meter long sailboat hull, a low-Reynolds number composite wing, a 2000 Watt-hour battery reservoir, a system of...
Show moreThe primary objective of this research is the development a wind and solar-powered autonomous surface vehicle (WASP) for oceanographic measurements. This thesis presents the general design scheme, detailed aerodynamic and hydrodynamic aspects, sailing performance theory, and dynamic performance validation measurements obtained from a series of experiments. The WASP consists of a 4.2 meter long sailboat hull, a low-Reynolds number composite wing, a 2000 Watt-hour battery reservoir, a system of control actuators, a control system running on an embedded microprocessor, a suite of oceanographic sensors, and power regeneration from solar energy. The vehicle has a maximum speed of five knots and weighs approximately 350 kilograms. Results from four oceanographic missions that were conducted in the Port Everglades Intracoastal Waterway in Dania Beach [sic] Florida are presented. Water temperature, salinity and oxidation-reduction measurements recorded during these missions are also discussed. The combination of a mono-hull and solid wing in an autonomous system is a viable design for a long-range ocean observation platform. The results of four near-shore ocean observation missions illustrate the initial capabilities of the design. Future work aimed to further reduce both the mass of the wing design and the power requirements of the system will increase performance in all operating conditions and should be considered. Furthermore, the progression of the legal framework related to ocean vehicles must be pursued with respect to unmanned autonomous systems.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166455
- Subject Headings
- Hydrographic surveying, Instruments, Evaluation, Aids to navigation, Equipment and supplies, Testing, Sailboats, Design and construction, Robots, Control systems, Oceanographic instruments, Evaluation
- Format
- Document (PDF)
- Title
- Evaluation of motion compensated ADV measurements for quantifying velocity fluctuations.
- Creator
- Lovenbury, James William., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study assesses the viability of using a towfish mounted ADV for quantifying water velocity fluctuations in the Florida Current relevant to ocean current turbine performance. For this study a motion compensated ADV is operated in a test flume. Water velocity fluctuations are generated by a 1.3 cm pipe suspended in front of the ADV at relative current speeds of 0.9 m/s and 0.15 m/s, giving Reynolds numbers on the order of 1000. ADV pitching motion of +/- 2.5 [degree] at 0.3 Hz and a heave...
Show moreThis study assesses the viability of using a towfish mounted ADV for quantifying water velocity fluctuations in the Florida Current relevant to ocean current turbine performance. For this study a motion compensated ADV is operated in a test flume. Water velocity fluctuations are generated by a 1.3 cm pipe suspended in front of the ADV at relative current speeds of 0.9 m/s and 0.15 m/s, giving Reynolds numbers on the order of 1000. ADV pitching motion of +/- 2.5 [degree] at 0.3 Hz and a heave motion of 0.3 m amplitude at 0.2 Hz are utilized to evaluate the motion compensation approach. The results show correction for motion provides up to an order of magnitude reduction in turbulent kinetic energy at frequencies of motion while the IMU is found to generate 2% error at 1/30 Hz and 9% error at 1/60 Hz in turbulence intensity.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362482
- Subject Headings
- Motion control systems, Fluid dynamic measurements, Fluid mechanics, Mathematical models, Analysis of covariance
- Format
- Document (PDF)
- Title
- Estimates of water turbine noise levels.
- Creator
- Guerra, Julian., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This work seeks to understand water turbine noise generation and to make preliminary estimations of the noise levels. Any structure attached to a turbine upstream its blades will generate unsteady fluctuating loads on the blade's surface, which are proportional to the radiated acoustic pressure. The noise levels of a simplified turbine based on existing designs surpass the ambient noise levels of the ocean at low frequencies ( 30 Hz).
Show moreThis work seeks to understand water turbine noise generation and to make preliminary estimations of the noise levels. Any structure attached to a turbine upstream its blades will generate unsteady fluctuating loads on the blade's surface, which are proportional to the radiated acoustic pressure. The noise levels of a simplified turbine based on existing designs surpass the ambient noise levels of the ocean at low frequencies (< 20 Hz) by approximately 50 dB ref 1 μPa and stay under the ambient noise levels at higher frequencies for a blade-passing frequency of 0.83 Hz and point of observation (100 m, 45 degrees, 45 degrees) from the hub. Streamlining the cross-section of the upstream structure as well as reducing its width decrease the noise levels by approximately 40 dB ref 1 μPa, at low frequencies and moderately increase them at higher frequencies. Increasing the structure-rotor distance decreases the noise levels with increasing frequencies (> 30 Hz).
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3170958
- Subject Headings
- Turbines, Vibration, Testing, Underwater acoustics, Fluid dynamics
- Format
- Document (PDF)
- Title
- Experiments and modeling on resistivity of multi-layer concrete with and without embedded rebar.
- Creator
- Liu, Yanbo., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Factors such as water to cement ratio, moisture, mixture, presence and depth of rebar, and dimension of specimens, all of which affect apparent resistivity of concrete, were analyzed by experimental and modeling methods. Cylinder and rectangular prism concrete specimens were used in the experiments exposed in a high moisture room, laboratory room temperature, high humidity and outdoor weather environments. Single rebar and four rebar specimens were used to study the rebar effect on the...
Show moreFactors such as water to cement ratio, moisture, mixture, presence and depth of rebar, and dimension of specimens, all of which affect apparent resistivity of concrete, were analyzed by experimental and modeling methods. Cylinder and rectangular prism concrete specimens were used in the experiments exposed in a high moisture room, laboratory room temperature, high humidity and outdoor weather environments. Single rebar and four rebar specimens were used to study the rebar effect on the apparent resistivity. Modeling analysis was employed to verify and explain the experimental results. Based on the results, concrete with fly ash showed higher resistivity than concrete with just ordinary Portland cement. Rebar presence had a significant effect on the measured apparent resistivity at some of the locations. The results could be used as a guide for field apparent resistivity measurements and provide a quick, more precise and easy way to estimate the concrete quality.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166452
- Subject Headings
- Reinforced concrete, Corrosion, Testing, Reinforcing bars, Properties, Concrete, Quality control
- Format
- Document (PDF)
- Title
- Concrete surface resistivity profiles along the splash zone on bridge piles exposed to sea water.
- Creator
- Suarez-Solano, Andres M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Prevention of the corrosion of steel reinforcement embedded in concrete is a constant challenge in engineering. A study of concrete surface resistivity versus elevation of partially immersed reinforced concrete structures in a marine splash zone has been developed and correlations made between concrete quality and chloride diffusion, i.e., aggressive ion permeability. A conditioning procedure was developed in which the concrete moisture content is increased by direct contact with fresh water...
Show morePrevention of the corrosion of steel reinforcement embedded in concrete is a constant challenge in engineering. A study of concrete surface resistivity versus elevation of partially immersed reinforced concrete structures in a marine splash zone has been developed and correlations made between concrete quality and chloride diffusion, i.e., aggressive ion permeability. A conditioning procedure was developed in which the concrete moisture content is increased by direct contact with fresh water for several days. The electrical resistivity of concrete is known to be primarily a function of the degree of water saturation. Correlations between field obtained concrete surface resistivity values versus chloride diffusivity, and between normalized resistivity measured on cores obtained from the field versus chloride diffusivity has been established. The resistivity values were measured on structures with different concrete mixes and various ages.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369390
- Subject Headings
- Reinforced concrete, Corrosion, Testing, Reinforcing bars, Properties, Concrete, Permeability, Concrete, Fluid dynamics
- Format
- Document (PDF)
- Title
- Corrosion initiation and propagation on corrosion resistant alloys embedded in concrete by accelerated chloride transport.
- Creator
- Gutierrez Tellez, Francisco., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Two duplex stainless steels rebars: UNS32304SS and UNS32101SS, were selected to investigate the corrosion initiation and propagation in reinforced concrete specimens. The investigation is divided in two phases with two different methods to accelerate the transport of chlorides through the concrete and initiate corrosion in a short period of time. After corrosion had initiated and propagated for some time; selected specimens were terminated for visual examination. On specimens selected for...
Show moreTwo duplex stainless steels rebars: UNS32304SS and UNS32101SS, were selected to investigate the corrosion initiation and propagation in reinforced concrete specimens. The investigation is divided in two phases with two different methods to accelerate the transport of chlorides through the concrete and initiate corrosion in a short period of time. After corrosion had initiated and propagated for some time; selected specimens were terminated for visual examination. On specimens selected for autopsy, the rebars in the top row showed corrosion to various degrees. Corrosion had propagated to such extent on the terminated specimens that the specimen showed cracks. Stray current might have caused accelerated corrosion on rebars where corrosion had initiated. Based on chloride concentrations measured at the rebar trace, corrosion initiated: on S32101 rebars on average at 7.9 kg/m3, and S32101 rebars on average at 6.0 kg/m3. The findings suggest that S32304 rebars corroded at a slower than S32101.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362380
- Subject Headings
- Concrete, Corrosion, Concrete construction, Reinforced concrete, Chemical resistance, Steel, Structural, Corrosion
- Format
- Document (PDF)
- Title
- Dynamic positioning and motion mitigation of a scaled sea basing platform.
- Creator
- Marikle, Sean P., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A 6-Degree Of Freedom (DOF) numeric model and computer simulation along with the 1/10th scale physical model of the Rapidly Deployable Stable Platform (RDSP) are being developed at Florida Atlantic University in response to military needs for ocean platforms with improved sea keeping characteristics. The RDSP is a self deployable spar platform with two distinct modes of operation enabling long distance transit and superior seakeeping. The focus of this research is the development of a Dynamic...
Show moreA 6-Degree Of Freedom (DOF) numeric model and computer simulation along with the 1/10th scale physical model of the Rapidly Deployable Stable Platform (RDSP) are being developed at Florida Atlantic University in response to military needs for ocean platforms with improved sea keeping characteristics. The RDSP is a self deployable spar platform with two distinct modes of operation enabling long distance transit and superior seakeeping. The focus of this research is the development of a Dynamic Position (DP) and motion mitigation system for the RDSP. This will be accomplished though the validation of the mathematical simulation, development of a novel propulsion system, and implementation of a PID controller. The result of this research is an assessment of the response characteristics of the RDSP that quantifies the performance of the propulsion system coupled with active control providing a solid basis for further controller development and operational testing.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/228767
- Subject Headings
- Inertial navigation systems, Mobile offshore structures, Design and construction, Wave motion, Theory of, Offshore structures, Dynamics, Feedback control systems
- Format
- Document (PDF)
- Title
- Development and experimental testing of an amphibious vehicle.
- Creator
- Marquardt, Joseph G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The development and experimental testing of the DUKW-Ling amphibious vehicle was performed during the first phase of an autonomous amphibious vehicle system development project. The DUKW-Ling is a 1/7th scale model of a cargo transport concept vehicle. The vehicle was tested in the three regions it is required to operate: land, sea and the surf zone region. Vehicle characteristics such as turning radii, yaw rate and velocities were found for different motor inputs on land and water. Also,...
Show moreThe development and experimental testing of the DUKW-Ling amphibious vehicle was performed during the first phase of an autonomous amphibious vehicle system development project. The DUKW-Ling is a 1/7th scale model of a cargo transport concept vehicle. The vehicle was tested in the three regions it is required to operate: land, sea and the surf zone region. Vehicle characteristics such as turning radii, yaw rate and velocities were found for different motor inputs on land and water. Also, because a vehicle navigating the surf zone is a new area of research that lacks experimental data the vehicle was tested in the breaking waves of the surf zone and its motion characteristics were found, as well as the drivetrain forces required to perform this transition. Maneuvering tests provided data that was used to estimate a model for future autonomous control efforts for both land and water navigation.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342208
- Subject Headings
- Motor vehicles, Amphibious, Design and construction, Naval architecture
- Format
- Document (PDF)
- Title
- Development and implementation of an adaptive controller for station keeping of small outboard-powered vessels.
- Creator
- Fisher, Aaron D., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In this thesis multiple controllers are developed which command a small boat with twin tied outboard motors to hold a desired position. In the process of developing a controller to hold a position, controllers were first developed which follow a desired heading or path over ground with the motors outputting constant thrust. These heading and path following controllers were tuned and tested in a numerical simulation, then validated on the R/V Lee and Ocean Power vessels through sea trials in...
Show moreIn this thesis multiple controllers are developed which command a small boat with twin tied outboard motors to hold a desired position. In the process of developing a controller to hold a position, controllers were first developed which follow a desired heading or path over ground with the motors outputting constant thrust. These heading and path following controllers were tuned and tested in a numerical simulation, then validated on the R/V Lee and Ocean Power vessels through sea trials in the Atlantic Ocean. After successful path following trials were performed, station keeping algorithms were developed and tuned in the numerical simulation, now with heading and thrust of the vessel both being variables to be controlled. After tuning in the numerical simulation, the Ocean power vessel was outfitted with systems for controlling throttle and steering with sea trials conducted in the Atlantic Ocean for station keeping.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2975247
- Subject Headings
- Ship handling, Stability of ships, Fracture mechanics, Boats and boating, Design, PID controllers, Computer simulation
- Format
- Document (PDF)
- Title
- Development of an integrated computational tool for design and analysis of composite turbine blades under ocean current loading.
- Creator
- Zhou, Fang., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A computational tool has been developed by integrating National Renewable Energy Laboratory (NREL) codes, Sandia National Laboratories' NuMAD, and ANSYS to investigate a horizontal axis composite ocean current turbine. The study focused on the design, analysis, and life prediction of composite blade considering random ocean current, cyclic rotation, and hurricane-driven ocean current. A structural model for a horizontal axis FAU research OCT blade was developed. Following NREL codes were used...
Show moreA computational tool has been developed by integrating National Renewable Energy Laboratory (NREL) codes, Sandia National Laboratories' NuMAD, and ANSYS to investigate a horizontal axis composite ocean current turbine. The study focused on the design, analysis, and life prediction of composite blade considering random ocean current, cyclic rotation, and hurricane-driven ocean current. A structural model for a horizontal axis FAU research OCT blade was developed. Following NREL codes were used: PreCom, BModes, ModeShape, AeroDyn and FAST. PreComp was used to compute section properties of the OCT blade. BModes and ModeShape calculated the mode shapes of the blade. Hydrodynamic loading on the OCT blade was calculated by modifying the inputs to AeroDyn and FAST. These codes were then used to obtain the dynamic response of the blade, including blade tip displacement, normal force (FN) and tangential force (FT), flap and edge bending moment distribution with respect to blade rotation.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362582
- Subject Headings
- Structural dynamics, Fluid dynamics, Marine turbines, Mathematical models, Turbines, Blades, Design and construction
- Format
- Document (PDF)
- Title
- Durability of carbon fiber/vinylester composites subjected to marine environments and electrochemical interactions.
- Creator
- Hasnine, Md., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Degradation of the Carbon Fiber/Vinylester (CF/VE) polymer matrix composites due to different electrochemical interactions when exposed to seawater or at high temperature had been experimentally investigated. Water uptake behavior of composite specimen was examined based on weight gain measurement. Three point bending test was performed to quantify the mechanical degradation of composite immersed in seawater with different environmental and electrochemical interactions. Finally,...
Show moreDegradation of the Carbon Fiber/Vinylester (CF/VE) polymer matrix composites due to different electrochemical interactions when exposed to seawater or at high temperature had been experimentally investigated. Water uptake behavior of composite specimen was examined based on weight gain measurement. Three point bending test was performed to quantify the mechanical degradation of composite immersed in seawater with different environmental and electrochemical interactions. Finally, Electrochemical Impedance Spectroscopy (EIS) was used to better understanding of the degradation process in CF/VE composite produced by interactions between electrochemical and different environmental conditions. A detailed equivalent circuit analysis by using EIS spectra is also presented in an attempt to elucidate the degradation phenomenon in composites.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2683124
- Subject Headings
- Composite materials, Mechanical properties, Fibrous composites, Structural analysis, Polymeric composites, Spectrum analysis
- Format
- Document (PDF)