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- Title
- Dynamic stability of fluid-conveying pipes on uniform or non-uniform elastic foundations.
- Creator
- Vittori, Pablo J., Florida Atlantic University, Elishakoff, Isaac, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The dynamic behavior of straight cantilever pipes conveying fluid is studied, establishing the conditions of stability for systems, which are only limited to move in a 2D-plane. Internal friction of pipe and the effect of the surrounding fluid are neglected. A universal stability curve showing boundary between the stable and unstable behaviors is constructed by finding solution to equation of motion by exact and high-dimensional approximate methods. Based on the Boobnov-Galerkin method, the...
Show moreThe dynamic behavior of straight cantilever pipes conveying fluid is studied, establishing the conditions of stability for systems, which are only limited to move in a 2D-plane. Internal friction of pipe and the effect of the surrounding fluid are neglected. A universal stability curve showing boundary between the stable and unstable behaviors is constructed by finding solution to equation of motion by exact and high-dimensional approximate methods. Based on the Boobnov-Galerkin method, the critical velocities for the fluid are obtained by using both the eigenfunctions of a cantilever beam (beam functions), as well as the utilization of Duncan's functions. Stability of cantilever pipes with uniform and non-uniform elastic foundations of two types are considered and discussed. Special emphasis is placed on the investigation of the paradoxical behavior previously reported in the literature.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13167
- Subject Headings
- Strains and stresses, Structural dynamics, Structural stability, Fluid dynamics, Vibration
- Format
- Document (PDF)
- Title
- Karhunen-Loeve decomposition for non stationary propulsor flow noise.
- Creator
- Kersulec, Jean-Luc., Florida Atlantic University, Glegg, Stewart A. L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The aim of this thesis is to develop a theory for non stationary propulsor flow noise. The model which is proposed is based on Amiet's paper "Acoustic Radiation from an Airfoil in a Turbulent Stream" [1], which describes broad band noise when a simple model of airfoil interacts with a turbulent flow, under the assumption of stationarity. The Karhunen-Loeve method provides a set of modes which describe the turbulent flow without the assumption of stationarity. A method is described to obtain...
Show moreThe aim of this thesis is to develop a theory for non stationary propulsor flow noise. The model which is proposed is based on Amiet's paper "Acoustic Radiation from an Airfoil in a Turbulent Stream" [1], which describes broad band noise when a simple model of airfoil interacts with a turbulent flow, under the assumption of stationarity. The Karhunen-Loeve method provides a set of modes which describe the turbulent flow without the assumption of stationarity. A method is described to obtain broad band noise calculations when the mean turbulent flow varies with time and produces non stationary turbulence. A comparison of the numerical results obtained with the results from the paper of reference [1] shows the characteristics of time varying sound radiation. The various mathematical formulae will give a starting point to the analysis of real time varying flows, which are not considered in this thesis.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13233
- Subject Headings
- Aerodynamic noise, Turbulence, Aerofoils, Unsteady flow (Aerodynamics), Nonlinear control theory, Differential equations, Nonlinear
- Format
- Document (PDF)
- Title
- Vibration tailoring of inhomogeneous beams and circular plates.
- Creator
- Pentaras, Demetris., Florida Atlantic University, Elishakoff, Isaac, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semi-inverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e...
Show moreThe vibrational behavior of inhomogeneous beams and circular plates is studied, utilizing the semi-inverse method developed by I. Elishakoff and extensively discussed in his recent monograph (2005). The main thread of his methodology is that the knowledge of the mode shape is postulated. The candidate mode shapes can be adopted from relevant static, dynamic or buckling problems. In this study, the exact mode shapes are sought as polynomial functions, in the context of vibration tailoring, i.e. designing the structure that possesses the pre-specified value. Apparently for the first time in the literature, several closed-form solutions for vibration tailoring have been derived for vibrating inhomogeneous beams and circular plates. Twelve new closed-form solutions for vibration tailoring have been derived for an inhomogeneous polar orthotropic plate that is either clamped or simply supported around its circumference. Also, the vibration tailoring of a polar orthotropic circular plate with translational spring is analyzed. There is considerable potential of utilizing the developed method for design of functionally graded materials.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13344
- Subject Headings
- Acoustical engineering, Plates (Engineering)--Vibration--Mathematical models, Buckling (Mechanics), Structural analysis
- Format
- Document (PDF)
- Title
- Analysis of factors affecting the sound generated by airboats.
- Creator
- Perez, Aquiles., Florida Atlantic University, Masory, Oren, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study presents an experimental and analytical investigation of the factors that affect the sound generated by airboats as well as the interaction among these factors; an airboat travels on water and wet land by means of an air pusher propeller attached to an internal combustion engine. These analyses show that the engine and propeller RPM are the main contributors of sound. The contribution of the engine is a tonal sound that is reduced by using a muffler. The sound generated by the...
Show moreThis study presents an experimental and analytical investigation of the factors that affect the sound generated by airboats as well as the interaction among these factors; an airboat travels on water and wet land by means of an air pusher propeller attached to an internal combustion engine. These analyses show that the engine and propeller RPM are the main contributors of sound. The contribution of the engine is a tonal sound that is reduced by using a muffler. The sound generated by the propeller is a flapping sound clearly identified at high revolutions (over 1800 RPM). Above mid-range speeds, the propeller sound takes over, and any reduction of sound on the muffler does not play any role. The only method to control the sound of an airboat without any design modifications is to maintain the operational RPM at mid-range when the muffler's devices contribute to the sound reduction.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13347
- Subject Headings
- Internal combustion engines--Noise, Noise control
- Format
- Document (PDF)
- Title
- Feasibility of target tracking for high speed high seas cargo transfer.
- Creator
- Tucker, Glenn C., Florida Atlantic University, Driscoll, Frederick R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
At sea cargo transfer has historically been a logistical challenge for both the military and the offshore industry. Even in moderate seas, three to five foot wave heights, extreme pendulations of cargo and large relative motions between vessels can occur that halts cargo transfer activities. This work develops a six-degree-of-freedom rigid crane dynamics model that is used to investigate the feasibility of crane target tracking which could extend and enhance offshore crane operations. A...
Show moreAt sea cargo transfer has historically been a logistical challenge for both the military and the offshore industry. Even in moderate seas, three to five foot wave heights, extreme pendulations of cargo and large relative motions between vessels can occur that halts cargo transfer activities. This work develops a six-degree-of-freedom rigid crane dynamics model that is used to investigate the feasibility of crane target tracking which could extend and enhance offshore crane operations. A double girder crane system is developed that easily adapts to different configurations and efficiently supports long reach heavy lift applications. Target tracking is feasible in sea states up to 5 when using the double girder crane. When compared to a present crane system, the target tracking crane requires, on average, only 3.65% more absolute total system power and 13.4% less continuous power, indicating that the proposed system should be realizable.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13388
- Subject Headings
- Cargo handling, Unitized cargo systems, Signal processing--Digital techniques, Ocean circulation--Mathematical models
- Format
- Document (PDF)
- Title
- Dynamic analysis of single- and multi-module platforms in waves.
- Creator
- Kling, Kaylie Ann., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The response of single- and multi-module floating platforms to surface waves is investigated theoretically. Wave exciting forces are computed using methods based on the Morrison equation and Froude-Krylov hypothesis. The radiation forces are obtained from experimental results of Vugt and where possible diffraction forces using the Haskind reciprocity relation. Heave and pitch response of a one-module platform and hinge-connected two-module platform are determined by integrating the...
Show moreThe response of single- and multi-module floating platforms to surface waves is investigated theoretically. Wave exciting forces are computed using methods based on the Morrison equation and Froude-Krylov hypothesis. The radiation forces are obtained from experimental results of Vugt and where possible diffraction forces using the Haskind reciprocity relation. Heave and pitch response of a one-module platform and hinge-connected two-module platform are determined by integrating the corresponding equations of rigid-body motion. A structural dynamic analysis is also carried out using the Green's function method to determine the elastic flexural response of the platform to waves. The results are compared with the experimental and numerical findings of others. The thesis contributes to a better understanding of rigid-body and elastic response of large ocean platforms subject to wave forces. The methodology is computationally less intensive and therefore can be effectively used for the design of platforms and the validation of numerical algorithms.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13399
- Subject Headings
- Ocean engineering, Wave motion, Theory of, Water waves--Mathematical models, Drilling platforms, Extreme value theory
- Format
- Document (PDF)
- Title
- Performance and limitations of acoustic positioning using a tetrahedral ultra-short baseline array and an acoustic modem source transmitting frequency-hopped sequences.
- Creator
- Mohamed, Asif I., Florida Atlantic University, Beaujean, Pierre-Philippe, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings,...
Show moreThe operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings, optimally combined through maximum likelihood estimation of the azimuth and elevation. A simulation has been implemented and experiments have been performed in a calibration tank. Model and experiments confirm that the accuracy of this system improves with the number of pulses and the signal-to-noise ratio. A mean positional error of 5.51% can be obtained with an SNR of 20 dB and a single processed pulse, the error decreases to 2.84% using six processed pulses.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13412
- Subject Headings
- Underwater navigation, Remote submersibles, Computer integrated manufacturing systems, Acoustical engineering, Underwater acoustics--Instruments
- Format
- Document (PDF)
- Title
- A PLANE RECTANGULAR ANISOTROPIC FINITE ELEMENT IN BENDING.
- Creator
- DADE, JOHN THOMAS., Florida Atlantic University, Brannock, Robert N., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A stiffness matrix of a finite element for a plane rectangular panel capable of resisting transverse loads and which may exhibit in-plane Hookean anisotropy is derived for use in structural analysis. A transverse deflection function is selected which is definable in terms of twelve parameters. The Principle of Virtual Work provides the relationship between forces and displacements by which the desired stiffness matrix is developed. Three displacements at each corner of the element yield...
Show moreA stiffness matrix of a finite element for a plane rectangular panel capable of resisting transverse loads and which may exhibit in-plane Hookean anisotropy is derived for use in structural analysis. A transverse deflection function is selected which is definable in terms of twelve parameters. The Principle of Virtual Work provides the relationship between forces and displacements by which the desired stiffness matrix is developed. Three displacements at each corner of the element yield twelve governing parameters. The energy method from the theory of elasticity is used to derive the expression for total strain energy in terms of the element's dimensions and the twelve governing parameters. The matrix is checked by principles of continuity and a rigid body displacement.
Show less - Date Issued
- 1972
- PURL
- http://purl.flvc.org/fcla/dt/13476
- Subject Headings
- Engineering, Civil
- Format
- Document (PDF)
- Title
- CORROSION OF CONCRETE COVERED REINFORCING STEEL IN A MARINE ENVIRONMENT RESULTING FROM STRAY CURRENT AND GALVANIC COUPLING.
- Creator
- MILLER, RONALD LAWRENCE., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
It is recognized that reinforced concrete structures are often susceptible to stray current corrosion damage. Experiments have been performed upon a reinforced concrete bridge model in sea water, and these indicate that 0.01 percent of stray direct current in this electrolyte may enter the structure. Alternating current may also contribute to corrosion of reinforcing steel, though experimental results reveal detection to be more difficult than for direct current. Two other sources of current...
Show moreIt is recognized that reinforced concrete structures are often susceptible to stray current corrosion damage. Experiments have been performed upon a reinforced concrete bridge model in sea water, and these indicate that 0.01 percent of stray direct current in this electrolyte may enter the structure. Alternating current may also contribute to corrosion of reinforcing steel, though experimental results reveal detection to be more difficult than for direct current. Two other sources of current in reinforcing steel are from cathodic protection systems of utility attachments and from galvanic coupling of the covered steel and bare steel. Mechanisms by which the above types of current contribute to deterioration of reinforced concrete structures are discussed.
Show less - Date Issued
- 1976
- PURL
- http://purl.flvc.org/fcla/dt/13772
- Subject Headings
- Steel--Corrosion
- Format
- Document (PDF)
- Title
- CRACKING OF CONCRETE DUE TO CORROSION OF VARIOUS EMBEDDED METALS.
- Creator
- TURNER, DEAN HUDSON., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit...
Show moreThe objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit of the investigation. Aluminum, cadmium, copper, and nickel were found to have no beneficial effect on concrete cracking as compared to steel. In addition, no correlation between oxide-metal volume ratio and concrete time-to-cracking could be observed. It was found that corrosion of molybdenum has little or no tendency to crack concrete and its corrosion potential and active behavior approximates that of steel, indicating it may be an excellent coating.
Show less - Date Issued
- 1976
- PURL
- http://purl.flvc.org/fcla/dt/13820
- Subject Headings
- Reinforced concrete--Cracking, Underwater concrete construction, Reinforced concrete--Corrosion
- Format
- Document (PDF)
- Title
- AN EXPERIMENTAL STUDY OF BIOFOULING ON A FLAT PLATE SUSPENDED IN A UNIFORM FLOW.
- Creator
- WOOD, MARK ALAN., Florida Atlantic University, Tennant, Jeffrey S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
An investigation was conducted to determine the relationship between hydrodynamic boundary layer parameters and biofouling growth rates. A summary of previous investigations of hydrodynamic effects on biofouling is presented. Wall shear stress is shown to be an important parameter and is described in detail. A submersible water tunnel was designed to allow investigation of a flat plate subject to a uniform flow of seawater. Parallel flow past a flat plate with a laminar boundary layer was...
Show moreAn investigation was conducted to determine the relationship between hydrodynamic boundary layer parameters and biofouling growth rates. A summary of previous investigations of hydrodynamic effects on biofouling is presented. Wall shear stress is shown to be an important parameter and is described in detail. A submersible water tunnel was designed to allow investigation of a flat plate subject to a uniform flow of seawater. Parallel flow past a flat plate with a laminar boundary layer was used to ensure that experimental conditions existed in which a known wall shear stress distribution was establised. Tests were conducted off Virginia Key in Miami, Florida. The results of the experiments clearly indicate the existance of a threshold value of shear stress which inhibits the attachment of the macrofouler under study, the acorn barnacle (Balanus spp.). Reported growth rates from other investigations are presented to substantiate results. Recommendations are made for additional hydrodynamic investigations in dealing with biofouling.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13849
- Subject Headings
- Fouling, Hydrodynamics
- Format
- Document (PDF)
- Title
- STRESS CORROSION CRACKING OF 7079-T651 ALUMINUM IN RESPONSE TO A CONSTANT STRESS INTENSITY.
- Creator
- SCOTT, DARWIN HAROLD, II., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Double cantilever beam specimens of 7079-T651 aluminum were subjected to low constant stress intensities in a sea water environment to determine the stress corrosion cracking response. In addition to a constant stress intensity some specimens were subjected to controlled, constant potentials. Despite the fact that all tests were in Region I of the crack growth rate-stress intensity curve, where the former has been projected to be very dependent upon the latter, a unique relationship between...
Show moreDouble cantilever beam specimens of 7079-T651 aluminum were subjected to low constant stress intensities in a sea water environment to determine the stress corrosion cracking response. In addition to a constant stress intensity some specimens were subjected to controlled, constant potentials. Despite the fact that all tests were in Region I of the crack growth rate-stress intensity curve, where the former has been projected to be very dependent upon the latter, a unique relationship between stress intensity and crack growth rate was not always indicated. Therefore, some variable other than stress intensity is assumed to control crack growth, particularly for the first several hundred hours of exposure. The observed behavior is discussed in terms of accepted theories of stress corrosion cracking in high strength aluminum alloys, including electrochemical dissolution and hydrogen embrittlement.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13878
- Subject Headings
- Stress corrosion, Aluminum--Corrosion
- Format
- Document (PDF)
- Title
- A TURBULENCE CURRENT METER DESIGN, CONSTRUCTION AND USE.
- Creator
- KIDERA, EDWARD HENRY, IV., Florida Atlantic University, Tennant, Jeffrey S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objectives of this investigation were - 1) design and build a turbulence current meter capable of measuring velocity fluctuations in a geophysical scale flow and 2) the measurement of such flow including subsequent analysis of near bottom turbulence. An unique device capable of sensing velocity fluctuations in the region 25cm above the bottom was constructed based on concepts original to the study of turbulence. A review of previous equipment and research is included for a comparison. The...
Show moreThe objectives of this investigation were - 1) design and build a turbulence current meter capable of measuring velocity fluctuations in a geophysical scale flow and 2) the measurement of such flow including subsequent analysis of near bottom turbulence. An unique device capable of sensing velocity fluctuations in the region 25cm above the bottom was constructed based on concepts original to the study of turbulence. A review of previous equipment and research is included for a comparison. The instrument's usefulness was illustrated in the open channel flow of a tidal estuary by its ability to detect the horizontal velocity field. The data obtained for the turbulence shows large variation in velocity of the lateral component on the order of 50-75% of the "mean" current speed. Digital filtering of the data reveals distinct structures of high energy, intermittent in their nature and analogous to "bursting". The energy spectrum of the longitudinal component follows the predicted slope of -1 for over two decades (.01 to 1.3 + Hz).
Show less - Date Issued
- 1978
- PURL
- http://purl.flvc.org/fcla/dt/13943
- Subject Headings
- Turbulence--Measurement, Water current meters
- Format
- Document (PDF)
- Title
- APPLICATION OF A MICROPROCESSOR TO ACOUSTIC DATA SAMPLING AND MANAGEMENT TASKS (AS APPLIED TO MANGANESE NODULE MINING).
- Creator
- MURPHY, DAVID PAUL, JR., Florida Atlantic University, Davidson, J. Blaine, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Methods of collecting information about the deep ocean sediments are considered. A compact, flexible data collection and management system based on microprocessor technology is developed. The hardware of the system is detailed and a typical software operating system is presented which controls sensor operations, stores temporary data and communicates with a shipboard computer system.
- Date Issued
- 1979
- PURL
- http://purl.flvc.org/fcla/dt/13987
- Subject Headings
- Microprocessors, Marine sediments--Sampling, Manganese nodules
- Format
- Document (PDF)
- Title
- A BED-LOAD TRANSPORT MEASURING DEVICE.
- Creator
- WU, MUO-CHUNG., Florida Atlantic University, Tennant, Jeffrey S., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objectives of this investigation were: (1) to find the relationship between the sand movement velocity and the force induced using a small model basin, (2) to find and build a sand transport meter and apply the relation from (1) together to measure the velocity fluctuation and quantity of sand movement on the beach. The idea of model basin comes from the fluidized bed concept. Using this model, the complicated influences that happen during the field measurement can be prevented, and a...
Show moreThe objectives of this investigation were: (1) to find the relationship between the sand movement velocity and the force induced using a small model basin, (2) to find and build a sand transport meter and apply the relation from (1) together to measure the velocity fluctuation and quantity of sand movement on the beach. The idea of model basin comes from the fluidized bed concept. Using this model, the complicated influences that happen during the field measurement can be prevented, and a prime relation can be applied to the field measurement. In the model basin experiment, the force induced by the drag is related to the velocity of power around 0. 62. In the field measurement on the beach, the initial goal could not be reached because of the appearance of the unexpected low frequency signal which was initiated by the wave motion itself. However, the device and idea of this experlment were proven to be good and feasible.
Show less - Date Issued
- 1980
- PURL
- http://purl.flvc.org/fcla/dt/14021
- Subject Headings
- Bed load--Measurement
- Format
- Document (PDF)
- Title
- STATIC STRESS ANALYSIS OF CHAIN LINKS USING A FINITE-ELEMENT METHOD.
- Creator
- TSENG, HUAN-SHOO HANS., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A static stress analysis of a common chain link and a pear-shaped nng ivas performed using the finite element structural analysis program SAP IV. The required finite element mesh and loading inputs were generated by the pre-processing program PRE-SAP- LINK. This procedure was used to determine the midplane stresses and displacements in a link and ring of typical sizes and subject to concentrated fcrces. Stress distributions and displacements were drawn by hand and by using a Tektronix 4662...
Show moreA static stress analysis of a common chain link and a pear-shaped nng ivas performed using the finite element structural analysis program SAP IV. The required finite element mesh and loading inputs were generated by the pre-processing program PRE-SAP- LINK. This procedure was used to determine the midplane stresses and displacements in a link and ring of typical sizes and subject to concentrated fcrces. Stress distributions and displacements were drawn by hand and by using a Tektronix 4662 Interactive Digital Plotter, respectively. The results obtained show that for both link and ring, the numerically largest principal stress and maximum in-plane shear stress occur on the element directly under an applied load . The entire procedure was verified by comparing the results obtained for the common link with experimental results in the literature and with analytical results obtained using a mechanics of materials approach. All of the results were in close agreement.
Show less - Date Issued
- 1980
- PURL
- http://purl.flvc.org/fcla/dt/14023
- Subject Headings
- Stress concentration
- Format
- Document (PDF)
- Title
- A PRELIMINARY STUDY OF WEAR OF AISI TYPE 304 STAINLESS STEEL AND MILD STEEL IN SEA WATER.
- Creator
- WENG, HARVEY H. L., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A fatigue machine was rebuilt to investigate the wear of mild steel and AISI Type 304 stainless steel while undergoing cyclic relative motions in air and sea water environments. Wear curves were obtained for both materials by measuring specimen weight loss as a function of the number of cycles of relative motion, and surface damage of the specimens was photographed. The results indicate that a sea water environment has a strong influence upon the wear characteristics of mild steel and 304...
Show moreA fatigue machine was rebuilt to investigate the wear of mild steel and AISI Type 304 stainless steel while undergoing cyclic relative motions in air and sea water environments. Wear curves were obtained for both materials by measuring specimen weight loss as a function of the number of cycles of relative motion, and surface damage of the specimens was photographed. The results indicate that a sea water environment has a strong influence upon the wear characteristics of mild steel and 304 stainless steel. For the mild steel, the corrosive effects of the sea water contributed to severe pitting and cracking of the wear surface and resulted in a significant increase in wear; after approximately 2.5 million cycles the amount of wear in sea water was approximately three times that in air. For the stainless steel, the sea water acted primarily as a lubricant and coolant, and served to reduce the amount of wear after 2.5 million cycles to about one-tenth of that in air.
Show less - Date Issued
- 1980
- PURL
- http://purl.flvc.org/fcla/dt/14031
- Subject Headings
- Steel--Fatigue--Environmental aspects, Steel, Stainless--Fatigue--Environmental aspects
- Format
- Document (PDF)
- Title
- DETECTION OF DETERIORATION OF REINFORCED CONCRETE BY ACOUSTIC EMISSION TECHNIQUES.
- Creator
- WENG, MING-YUAN., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques...
Show moreIn this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques provided a feasible method for detection of deterioration and cracking of steel reinforced structures in laboratory studies as well as in a field environment.
Show less - Date Issued
- 1980
- PURL
- http://purl.flvc.org/fcla/dt/14042
- Subject Headings
- Acoustic emission testing, Reinforced concrete--Corrosion
- Format
- Document (PDF)
- Title
- A METHOD OF ANALYSIS FOR EVALUATING THE EFFECTIVENESS OF PARTIAL DAMPING LAYER TREATMENTS FOR SQUARE PLATES.
- Creator
- KUNG, CHUN-HUA., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
An energy method for predicting the natural frequency and loss factor for square plates with partial and complete coatings is developed. Both simply-supported and edge-fixed bonndary conditions are considered. An impulse testing technique is used to provide an experimental verification of the analysis for the case of an edge-fixed square plate. The analytical and experimental results are in close agreement, and indicate that partial coatings can provide effective damping treatments.
- Date Issued
- 1981
- PURL
- http://purl.flvc.org/fcla/dt/14045
- Subject Headings
- Plates (Engineering)--Vibration, Damping (Mechanics)
- Format
- Document (PDF)
- Title
- INVESTIGATION AND ANALYSIS OF THE DILUTION AND DISPERSION OF WASTEWATER FROM AN OCEAN OUTFALL ON THE CONTINENTAL SHELF.
- Creator
- MURRAY, JAMES BURKE., Florida Atlantic University, Venezia, William A., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Experimental data fr6m a study of the Boca Raton ocean outfall on December 16, 1980 is presented. A vertical plane near the outfall was mapped using a Neil Brown CTD; a horizontal plane at a depth of one meter was profiled with a towed instrument platform housing two temperature probes and a fluorometer. The relevance of this data with respect to mathematical modeling is discussed. Coherence analysis of the sensor outputs show that temperature sensors alone cannot be used to reliably map the...
Show moreExperimental data fr6m a study of the Boca Raton ocean outfall on December 16, 1980 is presented. A vertical plane near the outfall was mapped using a Neil Brown CTD; a horizontal plane at a depth of one meter was profiled with a towed instrument platform housing two temperature probes and a fluorometer. The relevance of this data with respect to mathematical modeling is discussed. Coherence analysis of the sensor outputs show that temperature sensors alone cannot be used to reliably map the spreading effluent field.
Show less - Date Issued
- 1981
- PURL
- http://purl.flvc.org/fcla/dt/14064
- Subject Headings
- Ocean outfalls--Florida--Boca Raton
- Format
- Document (PDF)