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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Ocean Engineering and Technology
Journal Basic Information
Journal DOI :
Korean Society of Ocean Engineers
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Volume & Issues
Volume 15, Issue 4 - Nov 2001
Volume 15, Issue 3 - Aug 2001
Volume 15, Issue 2 - May 2001
Volume 15, Issue 1 - Feb 2001
Selecting the target year
A Study of the Hull Form of Oil Recovery Vessel by Using Magnetic Fluid
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 1~5
A study on the new active type oil-water separation system including the oil-water separation system of magnetic film was carried out. Separation system is composed of several active types of circulating oil separation steps and one magnetic film separation step at final stage. At the magnetic separation step, ferrofluid easily forms a weak magnetic mixture with oil, which is from the water by magnetic field gradient. The vessel has been designed to run at the maximum speed of 25 knots. And two typical forms of SWATH and Catamaran have been studied as a new type of oil recovery vessel.
Prediction of Wave Transformation in the Kwangan Beach
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 6~10
Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develope as wave-current equation type to investigate the effect of wave-current interaction. It starts from Berkhoff's(1972) mild slope equation and is transformed to time-dependent hyperbolic type equation by using variational principal. Finally the governing equation is shown as a parabolic type equation by splitting method. This wave-current model was applied to the kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.
Performance of the Submerged Dual Buoy/Membrane Breakwaters in Oblique Seas
Kee, S.T. ;
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 11~21
The focus of this paper is on the numerical investigation of obliquely incident wav interactions with a system composed of fully submerged and floating dual buoy/vertical-flexible-membrane breakwaters placed in parallel with spacing between two systems. The fully submerged two systems allow surface and bottom gaps to enable wave transmission over and under the system. The problem is formulated based on the two-dimensional multi-domain hydro-elastic linear wave-body interaction theory. The hydrodynamic interaction of oblique incident waves with the combination of the rigid and flexible bodies was solved by the distribution of the simple sources (modified Bessel function of the second kind) that satisfy the Helmholz governing equation in fluid domains. A boundary element program for three fluid domains based on a discrete membrane dynamic model and simple source distribution method is developed. Using this developed computer program, the performance of various dual systems varying buoy radiuses and drafts, membrane lengths, gaps, spacing, mooring-lines stiffness, mooring types, water depth, and wave characteristics is thoroughly examined. It is found that the fully submerged and floating dual buoy/membrane breakwaters can, if it is properly tuned to the coming waves, have good performances in reflecting the obliquely incident waves over a wide range of wave frequency and headings.
Resonance and Response of the Submerged Dual Buoy/Porous-Membrane Breakwaters in Oblique Seas
Kee, S.T. ;
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 22~32
The numerical investigation of obliquely incident wave interactions with fully submerged dual buoy/porous-membrane floating breakwaters placed in parallel with spacing is studied based on linear potential theory and Darcy's law. The numerical solutions are obtained by using a discrete-membrane dynamic model and second-kind modified Bessel function distribution over the entire boundaries of fluid regions. First, numerical solutions for an idealized dual submerged system without buoys are obtained. Second, a more practical dual submerged system with membrane tension provided by buoys at its tops is investigated by the multi-domain boundary element method particularly devised for dual buoy/porous-membrane problems with gaps. The velocity potentials of wave motion are coupled with porous-membrane deformation, and solved simultaneously since the boundary condition on porous-membrane is not known in advance. The effects of varying permeability on membranes and wave characteristics are discussed for the optimum design parameters of systems previously studied. The inclusion of permeability on membrane eliminates the resonances that aggravate the breakwater performance. The system is highly efficient when waves generated by the buoys and membranes were mutually canceled and its energy at resonance frequency dissipates through fine pores on membranes.
A Study of Artificial Reef Subsidence in Unsteady Flow Field
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 33~38
The subsidence characteristics of artificial reef (AFR) in the unsteady flow such as tidal flow were investigated. The scour and subsidence characteristics were confirmed in the steady flow field. In a main study, the interaction of "Flow - Sediment Movement - Structure Behavior" and scou
sidence mechanism were discussed int he unsteady flow field. AFR subsidence characteristics was discussed with Reynolds number(Re*), Shields number(Sn*), dimensionless acceleration of flow (af/g) and dimensionless time (t/T). Most of all, the continuous AFR subsidence from the scour was occurred by periodic behavior of AFR. This behavior is result from the asymmetric ground, and is influenced by maximum velocity, duration time and direction of flow.ow.
Effect of Circumferential Wall Heat Conduction on Boundary Conditions for Convection Heat Transfer from a Circular Tube in Cross Flow
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 39~45
With uniform heat generation from the inner surface of the cylindrical heater placed in a cross flow boundary condition, heat flow that is conducted along the wall of the heater creates a non-isothermal surface temperature and non-uniform heat flux distribution. In the present investigation, the effects of circumferential wall heat conduction on convection heat transfer is investigated for the case of forced convection around horizontal circular tube in cross flow of air. The wall conduction number which can be deduced from the governing energy equation should be used to express the effect of circumferential wall heat conduction. It is demonstrated that the circumferential wall heat conduction influences local Nusselt numbers of one-dimensional and two-dimensional solutions.
Study on Creep Life Prediction by Initial Strain Method for Friction Welded Joints of Heat Resisting Steels
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 46~52
In this paper, the real-time prediction of high temperature creep life was carried out for the friction welded joints of dissimilar heat resisting steels (SUH3-SUH35). various life prediction method such as LMP (Larson_miller Parameter) and ISM (initial strain method) were applied. The creep behaviors of those steels and the welds under static load were examined by ISM combined with LMP at 500, 600 and
, and the relationship between these two methods was investigated. A real-time creep lie (tr, hr) prediction equation by initial strain (
, %) under any creep stress (
, MPa) at any high temperature (T, K) was developed as follows:
for SUH3-SUH35 friction weld of =16mm and 20mm, respectively.
Friction Welding of Dissimilar Hot Die Punch materials and Its Creep Life Prediction(II)-Creep Life Prediction by ISM
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 53~60
It was confirmed that the life predictive equation by LMP and LMP-ISM are effective only up to 10
hours and can not be used for long times of
hours, but that by ISM can be used for long times creep life prediction with more reliability. The predictive creep life equation of ISM has better reliability than those by LMP and LMP-ISM, and its realizably is getting better for long time creep prediction(
Acoustic Emission and Indentation Fracture Method for the Engineering Ceramics
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 61~65
The fracture toughness of ceramics can be measure by such various methods as DT (double torsion), CN (chevron notch) etc. But, the application of these methods to the engineering ceramics is very difficult because of its very high hardness. So, IF (indentation fracture) method is generally used for the evaluation of fracture toughness of ceramics. The Median crack induced by the sharp Vickers indenter was compared with the detected AE (acoustic emission) signal. On the silicon nitride ceramics, the AE test results agree fairly well with the median crack occurance and growth process. But, on the alumina, very many complicated crack signals were detected besides median crack. It can be considered that the IF methods must be used in limited engineering ceramics materials.
The Sectional Analysis of Trunk-lid using the Equilibrium Approach and Three-Dimensional Shape Composition
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 66~71
A sectional analysis of trunk-lid carried out by using the equilibrium approach based on the force balance together with geometric relations and plasticity theory. In computing a force balance equation, it is required to define a geometric curve approximating the shape of sheet metal at any step of deformation from the interaction between the die and the deformed sheet. The trunk-lid panel material is assumed to possess normal anisotropy and to obey Hill's new yield criterion. Deformation of each section of trunk-lid panel is simulated and composed to get the three-dimensional shape by using CAD technique. It was shown that the three-dimensional shape composition of the two-dimensional analysis.
A Study on the Influence of the Punch Stroke of Bead on the Draw-bead process by using Static-explicit Finite Element Method
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 72~78
The bead is used to provide properly restraining force in the sheet metal forming process. This bead process includes bending and geometrical non-linearity, and affects the state of binderwrap. Therefore, the analysis of bead process is very important to obtain the desired formability. In this paper, the research about the influence of the punch stroke of bead on the draw-bead process was conducted. Results from the analysis will give useful information to the effective tool design of blank forming process. To analyze the bead process, and elasto-plastic finite element formulation is constructed from the equilibrium equation and the considered boundary conditions involved a proper contact condition. The static-explicit finite element method as a numerical method for the analysis was applied to the analysis program code. It was found that this method could solve too much computation time and convergence problem owing to high non-linearity of bead forming process.
Study on Friction Welding of Heat resisting Steel Materials and Its Real Time Evaluation by AE
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 79~87
In this paper, not only the development of optimizing of friction welding with more reliability and more applicability but also the development of in-process real-time weld quality (such as strength and toughness) evaluation technique by acoustic emission for friction welding of the engine exhaustive valve (SUH3-SUH35 dissimilar steels of 12.3mm, 16mm, 20mm, and 24mm in diameters) were performed, comparing with the other FRW matches of materials such as SUH3 to SUH31, STS303 and SUH3 to STS304. As an important result, the techniques for dissimilar friction welding optimization of engine heat resisting steels SUH3 and SUH35 (12.3mm, 16mm, 20mm, and 24mm) and its real-time weld quality evaluation by AE was developed, considering on both diameter and carbon equivalent effects.
Study on Optimization of Dissimilar friction Welding of Nuclear Power Plant Materials (Cu Alloy/STS316L) and Its Real Time AE Evaluation
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 88~93
In this paper, joints of Cu-1Cr-0.1Zr alloy to STS316L were performed by friction welding method. Particularly, Cu-1Cr-0.1Zr alloy is attractive candidate as nuclear power plant material and exibit the best combination of high strength and good electrical and thermal conductivity of any copper alloy examined. The stainless steel is a structural material while copper alloy acts as a heat sink material for the surface heat flux in the first wall. So, in this paper, not only the development of optimizing of friction welding with more reliability and more applicability but also the development of in-process real-time weld quality (such as strength and toughness) evaluation technique by acoustic emission for friction welding of such nuclear reactor component of Cu-1Cr-0.1Zr alloy to STS316L steel sere performed.
Life Prediction of Fatigue Crack Propagation and Nondestructive Evaluation in 5083 Aluminum Alloy
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 94~98
fatigue life and nondestructive evaluation were examined experimentally using surface crack specimen and compact tension specimen of 5083 aluminium alloy. Acoustic emission signals emanated during failure of aluminum alloys has been the subject of numerous investigations. Possible sources of AE during deformation have been suggested as the dislocations, fracture of brittle particles and debonding of these particles from the alloy matrix. Fatigue life and penetration behavior of long surface crack can be evaluated quantitatively using K values proposed by authors. The influence of stress ratio on the frequency characteristics of AE signals were investigated.
Evaluation on High Temperature Fracture toughness of Pressure Vessel SA516/70 Steel
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 99~104
Elastic-plastic fracture toughness
can be used as an effective design criterion in elastic plastic fracture mechanics. Most of these systems are
value at high temperature must be determined for use of integrity evaluation and designing of such systems. Elastic-plastic fracture toughness
tests were performed on SA516/70 carbon steel plate and test results were analyzed according to ASTM E 813-87, ASTM E 813-89 and ASTM E 1152-87.safety and integrity are required for reactor pressure vessels because, they are operated in high temperature. There are single specimen method, which used as evaluation of safety and integrity for reactor pressure vessels. In this study, elastic-plastic fracture toughness(
) and J-
a of SA 516/70 steel used as reactor pressure vessel steel are measured and evaluated at room temperature, 150
according to unloading compliance method.
A Study on Fatigue Crack propagation Behavior of Pressure Vessel Steel SA516/70 at High Temperature
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 105~110
The fatigue crack propagation behavior of the SA516/70 steel which is used for pressure vessels was examined experimentally at room temperature, 150
with stress ratio of R=0.1 and 0.3. The fatigue crack propagation rate da/dN related with the stress intensity factor range
was influenced by the stress ratio within the stable growth of fatigue crack(Region II) with an increase in
. The resistance to the fatigue crack growth at high temperature is higher in comparison with that at room temperature, and the resistance attributed to the extent of plasticity-induced by compressive residual stress according to the cyclic loads. Fractographic examinations reveal that the differences of the fatigue crack growth characteristics between room and high temperature are mainly explained by the crack closure and oxide-induced by high temperature.
Effect of Molding Condition on Mechanical properties during Joining of GMT-Sheet
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 111~119
The application as the parts of an automobile, using the property of GMT-Sheet, is increasing. In order to exchange the parts of an automobile for GMT-Sheet, at first, the establishment and problem of exact joining strength must be determined. We have studied it using composites which is not same each other fiber oriented condition so as to determine joining strength and joining condition of GMT-Sheet. In this study, the result of experiment of forming condition concerned joining problem of GMT-Sheet is this; joining efficiency of GMT-Sheet, increases as lap joint length L increases. Increase of compression ratio causes decrease of joining efficiency after of GMT-Sheet joining. In the viewpoint of recycling, randomly oriented composite of GMT-Sheet is desirable more than unidirectional oriented composite. We has better design the structure so as not to occur to stress centralization on the joining part.
Ultimate Strength Analysis of Ring-stiffened Cylinders Using Commercial softwares (I)
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 120~123
Despite the increasing necessity of accurate estimation of ring-stiffened cylinders'ultimate strength, the complex structural behavior of cylinders has made their design mainly depend on empirical formulas mostly based on limited test data rather than theoretical background. This paper has developed the imperfection method which enables the ultimate strength analysis of buckling-sensitive structures by combining two separate functions covered by common commercial finite element softwares, which are linear elastic buckling analysis and nonlinear stress analysis. Developed method was applied to two of the world most renowned softwares, MSC/NASTRAN and ABAQUS, for the analysis of ring-stiffened cylinders and unexpectedly big difference in their analysis results was found. This tells that many widely used commercial softwares have their different strong points and weak points and the choice of commercial software should be cautiously made after thorough inspection. This paper ends with some useful information about which of the two aforementioned softwares is more respectively for the linear elastic buckling analysis and the ultimate strength analysis of ring-stiffened cylinders.
Characteristics of Bending Strength on Coating Condition of Metal Surface Polyurethan Coating Material
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 124~129
The research on anticorrosive of valve for ship, waterworks, and drainage system is very important. The purpose of this paper is to develop the metal/polyurethan adhesive technique at insider of the value to prevent corrosion in the value. It is performed to the bending strength test by using metal /polyurethan in the metals (SB41, Al6061). It is investigated to the effects of bending strength on curing temperature, preheating time and curing time, and to the fracture mechanism of metal/polyurethan adhensived specimen. As a results, we find that the bending strength is the highest at curing temperature of 11
and the curing time is 60 minutes in metal/polyurethan adhesive specimen.
A Study on Development of a Pyrolysis Characteristics for Combustible Ocean waste
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 130~134
Recently environmental pollution at sea becomes serious, so every governmental organization makes its effort to solve this problem. Combustible ocean wastes as of ropes, fishing nets, and tires are usually highly polymerized compound materials. The problem of ocean waste treatment can be solved by using the pyrolysis method. Pyrolysis characteristics of ocean waste was examined to get the basic data for the production system of fuel from the ocean waste. Thermogravimetric experiment showed that residual mass rate decreases as the velocity of temperature-rising becomes lower. The pyrolysis of waste rope and fishing net occurs at 300~450
and the waste tire does at 350~450
. Pyrolysis time is estimated about 15 to 20 minutes in the temperature range when lively act of pyrolysis temperature reached.
Influence of a Moving Mass on Dynamic Behavior of a Simply Supported Pipe Conveying Fluid
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 135~140
A simply supported pipe conveying fluid and a moving mass upon it constitute a vibrational system. The equation of motion is derived by using Lagrange's equation. The influence of the velocity and the inertia force of a moving mass and the velocities of fluid flow in the pipe have been studied on the dynamic behavior of a simply supported pipe by numerical method. The velocities of fluid low are considered within its critical values of the simply supported pipe without a moving mass upon it. Their coupling effects on the transverse vibration of a simply supported pipe are inspected too. as the velocity of a moving mass increases, the deflection of midspan of a simply supported pipe conveying fluid is increased and the frequency of transverse vibration of the pipe is not varied. Increasing of the velocity of fluid flow makes the frequency of transverse vibration of the simply supported pipe conveying fluid decrease and the deflection of midspan of the pipe increase. The deflection of the simply supported pipe conveying fluid is increased by a coupling of the moving mass and the velocities of a moving mass and fluid flow.
Influential Parameters on Offshore Jacket Structure Launching
Journal of Ocean Engineering and Technology, volume 15, issue 2, 2001, Pages 141~147
The launching process is one of the most critical operations for large structure in offshore installation. Since as the size increases it limits the availability of offshore crane facilities, the large jacket structures are often installed by launching. As the structure approaches to tilt beam, it reaches critical load, and there are parameters to affect on launching procedure. The major influential parameters are trim, draft of barge, center of gravity, center of buoyancy and reserved buoyancy of jacket. As increasing of trim and draft, structural loads tend to decrease. The trim is found to be more contributing than draft on structural loads. Therefore the trim should be increased so as to decrease structural loads and to avoid stalling of structure and submergence of stern. During the launching process, the distance between jacket and seabed should be investigated which differs from the amount of reserved buoyancy and launching condition of barge. In this paper the effects of parameters on launching process are numerically investigated.