• 대한조선학회논문집
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• 제47권4호
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• pp.508-516
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• 2010

This study aims at investigating the effect of the chamfer on the liquid sloshing in the three-dimensional (3D) rectangular tank. In order to simulate the 3D incompressible viscous two-phase flow in the 3D tank with partially filled liquid, the present study has adopted the volume of fluid (VOF) method based on the finitevolume method which has been well verified by comparing with the results of the relevant previous researches. The effects of the chamfering top corners of the tank on the liquid sloshing characteristics have been investigated. The angle of the chamfering top corners (${\theta}$) has been changed in the range of $0^{\circ}{\leq}{\theta}{\leq}60^{\circ}$(${\Delta}{\theta}=15^{\circ}$) to observe the free surface behavior, and the effect on wall impact load. Generally, as the angle of the chamfering top corners increases, the impact pressure on the upper knuckle point decreases. However it seemed that a critical angle of the chamfering top corners exists to reveal the lowest impact pressure on the wall.

• Geomechanics and Engineering
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• 제31권4호
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• pp.375-384
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• 2022

The variation of the undrained shear strength (c_u) is an important consideration for assessing slope stability in engineering practice. Previous studies focused on the three-dimensional (3D) stability of slopes in normally consolidated clays generally assume the undrained shear strength increases linearly with depth but does not vary in the horizontal direction. To assess the 3D stability of slopes with spatially varying undrained shear strength, the kinematic approach of limit analysis was adopted to obtain the upper bound solution to the stability number based on a modified failure mechanism. Three types failure mechanism: the toe failure, face failure and below-toe failure were considered. A serious of charts was then presented to illustrate the effect of key parameters on the slope stability and failure geometry. It was found that the stability and failure geometry of slopes are significantly influenced by the gradient of c_u in the depth direction. The influence of c_u profile inclination on the slope stability was found to be pronounced when the increasing gradient of c_u in the depth direction is large. Slopes with larger width-to-height ratio B/H are more sensitive to the variation of c_u profile inclination.

• Advances in materials Research
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• 제3권1호
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• pp.237-257
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• 2014

In this paper, we adopted a two-dimensional analytical electro-elastic model to predict the stress distributions of the piezoelectric actuator in 3D case. The actuator was embedded in an elastic host structure under electrical loadings. The problem is reduced to the solution of singular integral equations of the first kind. The interfacial stresses and the axial normal stress in both plane stress state and plane strain state were obtained to study the actuation effects being transferred from the actuator to the host. The stress distributions of the PZT actuator in different length and different thickness were analyzed to guarantee the generality. The validity of the present model has been demonstrated by application of specific examples and comparisons with the corresponding results obtained from the Finite Element Method.

• 대한조선학회논문집
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• 제48권6호
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• pp.544-551
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• 2011

The internal flows of moonpool usually causes huge added resistance on drillships, and those are very complex to analyze. Therefore, not only experimental approaches but also numerical simulations are required for better investigations when dealing with the hydrodynamic problems of moonpool. In the present research, numerical simulations are used to find out why the resistance increases by moonpool on a running drillship. That is, the three-dimensional numerical simulations and model tests are carried out to examine the characteristics of internal flow and added resistance by changing the section of the moonpool in both longitudinal and transverse directions. Finally, based on the present studies, an optimized shape of the moonpool is suggested, which effectively reduces added resistance, and that is confirmed with three-dimensional numerical simulations and model tests.

• 한국수소및신에너지학회논문집
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• 제26권5호
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• pp.438-444
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• 2015

This study describes the effect of T branch shape on internal flow characteristics inside itself. Continuity and three-dimensional Reynolds-averaged Navier-Stokes equation have been used as governing equations for the numerical analysis. The T branch was modeled assuming that it is used for Alaska pipeline project which was planned to provide reliable transportation of natural gas from ANS to Alaska-Yukon border. Therefore the characteristics of T branch and operating condition of pipeline were from report of Alaska pipeline project. The nine T branch shapes were analyzed and the mass flow rate ratio between mainline and branch was assumed to be 0.95 : 0.05, 0.9 : 0.1, 0.85 : 0.15. The results shows that there are typical flow patterns in T branch and the shape of T branch makes some differences to the internal flow of branch rather than mainline.

• 건축역사연구
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• 제7권4호
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• pp.29-47
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• 1998

The aim of this study is to understand the original methods of architectural composition in F. L. Wright's works, For this purpose, the principal thoughts based on his organic architecture was examined over all others, and the results of this study are as follows. 1. F. L. Wright knew Taoist Philosophy, especially Lao-tzu's thought about space based on traditional oriental arts included traditional japanese arts by his superior intuition. this is similar to Froebel Thought in the principal theory, that is, his own unique field of abstract architectural education with three-dimensional geometry learned through Froebel Gifts. 2. Space is reality ; such Lao-tzu's thought, reversed the sense of values, influenced F. L. Wright's way to accomplish his own continuous space. that is to say, he attempted taking precedence of spatial organization by the unit of three-dimensional module made the substance, Froebel Blocks (3, 4, 5, 6 Gifts) into non-substance, and trying to do the methods of continuous liberal composition in architecture. which is his original accomplishment, namely his mentioned 'democratic' because of judging the space and the mold of architecture as individualities. 3. F. L. Wright treated the space as a positive entity, so that he created his own architecture organically combined with spaces and forms. : This was the result that he comprehended both formative, physical worth in West and spatial, non-physical worth in East as equivalence. It is understood that F. L. Wright's works combined with East and West are the significance of his architecture and the progress of true internationalities and modernization in modern architecture. 4. From the analyses of his works, we knew the fact that F. L. Wright's architecture, especially in the spatial organization were performed by the reasonable methods with geometric system of Froebel Gifts. In the observation of our fundamental way of thinking on his architecture, this study shows the necessity to let us get out of preconceptions and conclusions that the organic architecture is mysterious and difficult, but to systematize and put his organic methods to practical use.

• 한국조경학회지
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• 제32권3호
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• pp.106-113
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• 2004

The shapes(mass) of buildings are determined by many interrelated factors, such as planning and building regulations, the size and shape of building parcels, and adjoining road conditions. Understanding the effects of the determinants on the building shapes is not a simple task because of the multiplicity and complex interrelationships of the determinants. This study developed a prototype of three dimensional computer model that can simulates the determination process of building shape using GIS and CAD techniques. A commercial block in the south of Seoul was selected for the case study. Several methods of building height control were applied, and their effects on the cityscape were evaluated. The results shows that the three dimensional computer modelling offers an effective means for evaluating the effects of planning and building regulations. The implication of the case study and future research directions were discussed.

• Structural Engineering and Mechanics
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• 제5권5호
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• pp.625-634
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• 1997

Reinforced concrete (RC) interior beam-column joints with high-strength materials: concrete compressive strength of 100 MPa and the yield strength of longitudinal bars of 685 MPa, were analyzed using three-dimensional (3-D) nonlinear finite element method (FEM). Specimen OKJ3 of joint shear failure type was a plane interior joint, and Specimen 12 of beam flexural failure type was a 3-D interior joint with transverse beams. Though the analytical initial stiffness was higher than experimental one, the analytical results gave a good agreement with the test results on the maximum story shear forces, the failure mode.

• 대한조선학회논문집
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• 제44권5호
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• pp.474-481
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• 2007

A three-dimensional finite element model has been used to simulate the bead on plate welding of curved steel plates having curvature in the welding direction. By using traditional method such as thermal-elastic-plastic(TEP) finite element analysis. the weld-induced deformation can be accurately predicted. However, three-dimensional finite element analysis is not practical in analyzing the weld-induced deformation of large and complex structures such as ship structures in view of computing time and cost. In this study, used is the equivalent loading method based on inherent strain to illustrate the effect of the longitudinal curvature upon the weld-induced deformation of curved plates.

• Journal of Advanced Research in Ocean Engineering
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• 제4권4호
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• pp.185-194
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• 2018

In this study, the extreme sloshing pressure was predicted using various statistical models: three-parameter Weibull distribution, generalized Pareto distribution, generalized extreme value distribution, and three-parameter log-logistic distribution. The estimation of sloshing impact pressure is important in design of liquid cargo tank in severe sea state. In order to get the extreme values of local impact pressures, a lot of model tests have been carried out and statistical analysis has been performed. Three-parameter Weibull distribution and generalized Pareto distribution are widely used as the statistical analysis method in sloshing phenomenon, but generalized extreme value distribution and three-parameter log-logistic distribution are added in this study. Additionally, statistical distributions are fitted to peak pressure data using three different parameter estimation methods. The data were obtained from a three-dimensional sloshing model text conducted at Seoul National University. The loading conditions were 20%, 50%, and 95% of tank height, and the analysis was performed based on the measured impact pressure on four significant panels with large sloshing impacts. These fittings were compared by observing probability of exceedance diagrams and probability plot correlation coefficient test for goodness-of-fit.