• Journal of the Korean Society of Costume
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• v.50 no.4
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• pp.147-164
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• 2000

This thesis examines the origin, the change and the symbolic meanings of class representation, and offers a comparative study on the differences of class representation in the history of Korean and western costume on the basis of class representation methods and types shown from ancient times to 18C. In both eastern and western costume, the differences in status are commonly represented in the width and length of costume, color, textile, ornamental design, wearing, decoration, etc. The costume of noble class was wide and long, while that of common class was narrow and short so that it could be convenient for them to move around. Especially, from 16C to 18C in the west the costume of noble class was expanded to the extent that it was inconvenient for them to move around not only by skirt swelling by using hoop, but also by pad, ruff, lace, etc. This appears to show that they are not working class. Wearing and decoration of noble class were much more colorful, complicated and varied, while those of common class were simple and plain. In the west, the wearing of chiton and toga in Greece and Rome was different depending on social status. More specific look at the differences in class representation shown in the eastern and western costume reveals that the higher the rank, the more the women in both Gothic and Chosun period covered the body, thereby representing rank. In 18C, the women in both Rococo and Chosun period commonly showed excessive decoration and lavishness on their hair, and in this period the width of skirt was also commonly expanded to the longest extent, with a slight difference put aside.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1337-1347
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• 2013

The parametric analysis on ultimate behavior of buried cylindrical GFRP(Glass Fiber Reinforced Polymer) septic tank was presented. Two kinds of F.E. analysis model(soil-spring model and 3D full model) was constructed. The ultimate behavior of septic tank was investigated according to the size of stiffened steel ring and properties of underground soil. Ramberg-Osgood model and Druker-Prager model were used for material nonlinear characteristics of GFRP septic tank and soil, respectively. The diameter and thickness of stiffened steel ring inside septic tank, elastic modulus and internal friction angle of soil were selected for parametric variables. The ultimate behavior of septic tank, load-displacement, axial and hoop strain, were calculated and investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.409-414
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• 2017

In the thin strip coiling process, it is necessary to use a sleeve with a mandrel to prevent excessive deformation of the strip. The stress distribution in the sleeve and strip is an important factor to determine the size of the sleeve. However, an experimental approach is almost impossible because of the accumulation of high pressure. A finite element (FE) model of the strip coiling process was developed in this study. Then, the radial and hoop stresses on the sleeve and strip were investigated using FE analyses. The theoretical values and analysis results under idealized conditions were compared to verify the FE model. The effect of the strip thickness on the stress distribution was also investigated. The radial stress increased by 6.3 times for a 1-mm-thick strip at the coil starting point. The radial stress at the sleeve increased by 14.8 % with a stacked thickness of 90 mm because of the reaction force applied by the mandrel.

• Steel and Composite Structures
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• v.20 no.5
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• pp.1067-1085
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• 2016

Recent research on steel moment-resisting connection between steel beams and concrete filled steel tubes has shown that there are considerable advantages to be obtained by anchoring the connection to the concrete infill within the tube using anchors in blind bolts. In the research reported here, extensive experimental tests and numerical analyses have been performed to study the anchorage behaviour of cogged deformed reinforcing bars within concrete filled circular steel tubes. This data in essential knowledge for the design of the steel connections that use anchored blind bolts, both for strength and stiffness. A series of pull-out tests were conducted using steel tubes with different diameter to thickness ratios under monotonic and cyclic loading. Both hoop strains and longitudinal strains in the tubes were measured together with applied load and slip. Various lead-in lengths before the bend and length of tailed extension after the bend were examined. These dimensions were limited by the dimensions of the steel tube and did not meet the requirements for "standard" cogs as specified in concrete standards such as AS 3600 and ACI 318. Nevertheless, all of the tested specimens failed by bar fracture outside the steel tubes. A comprehensive 3D Finite Element model was developed to simulate the pull-out tests. The FE model took into account material nonlinearities, deformations in reinforcing bars and interactions between different surfaces. The FE results were found to be in good agreement with experimental results. This model was then used to conduct parametric studies to investigate the influence of the confinement provided by the steel tube on the infilled concrete.

• Steel and Composite Structures
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• v.33 no.6
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• pp.793-803
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• 2019

Concrete-filled steel tubular (CFST) beam-columns are widely used owing to their good performance. They have high strength, ductility, large energy absorption capacity and low costs. Externally stiffened CFST beam-columns are not used widely due to insufficient design equations that consider all parameters affecting their behavior. Therefore, effect of various parameters (global, local slenderness ratio and adding hoop stiffeners) on the behavior of CFST columns is studied. An experimental study that includes twenty seven specimens is conducted to determine the effect of those parameters. Load capacities, vertical deflections, vertical strains and horizontal strains are all recorded for every specimen. Ratio between outer diameter (D) of pipes and thickness (t) is chosen to avoid local buckling according to different limits set by codes for the maximum D/t ratio. The study includes two loading methods on composite sections: steel only and steel with concrete. The case of loading on steel only, occurs in the connection zone, while the other load case occurs in steel beam connecting externally with the steel column wall. Two failure mechanisms of CFST columns are observed: yielding and global buckling. At early loading stages, steel wall in composite specimens dilated more than concrete so no full bond was achieved which weakened strength and stiffness of specimens. Adding stiffeners to the specimens increases the ultimate load by up to 25% due to redistribution of stresses between stiffener and steel column wall. Finally, design equations previously prepared are verified and found to be only applicable for medium and long columns.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.73-79
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• 2001

The corner protection which is consist of insulation and $9\%$ nickel liner is designed to mitigate the high hoop tension at the corner of LNG storage tank by LNG leakage. So the design loads depend on thermal and liquid pressure from leaked LNG In this paper design conditions are suggested as operating, major and minor leak conditions. And in order to check integrity of comer protection for the design conditions by appendix 4 in ASME section VIII div.2, acceptability checking process that have stress categorization and finite element analysis is explained.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.30-34
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• 2011

This paper presents a strength safety evaluation of composite pressure container for hydrogen fuel tanks with a storage capacity of 104 liter and 70MPa pressure. The carbon fiber composite container is manufactured by an aluminum liner of Al6061-T6 and composite multi-layers of hoop winding layer in circumferential direction, $12^{\circ}C$ inclined winding layer and $70^{\circ}C$winding layer in helical direction respectively. The FEM results on the strength safety of composite fuel tanks were evaluated with a criterion of design safety of US DOT-CFFC and KS B ISO 11119-2 codes. The FEM computed results indicate that the proposed design model of 104 liter composite container is safe based on two strength safety codes. But, the computed results of carbon fiber fuel tanks based on US DOT-CFFC code is safer compared with that of KS B ISO 11119-2. Thus the hydrogen gas pressure container of 70MPa may be evaluated and designed by US DOT-CFFC code for more strength safety.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.1-8
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• 2013

In this study, 120 cases of damage due to ground subsidence of city gas pipeline which is hanging on apartment outer wall were investigated. From the survey results, it was determined to be approximately 100m~200mm ground subsidence occurred and at severe damage, pipeline was cut and the gap was about 50mm between two cut pipeline. Device for measuring the amount of deformation of standing gas pipeline was designed and fabricated. And installed it on apartment outer wall for measuring the deformation due to ground subsidence, after 5 months measurement the amount of ground subsidence was measured to 1.3mm. Stress assessment was conducted based on results of ground subsidence occurred on standing gas pipeline.

• Architectural research
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• v.20 no.1
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• pp.17-25
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• 2018

Countermeasures against earthquake disasters such as the seismic capacity evaluation and/or retrofit schemes of buildings, especially existing low-rise reinforced concrete buildings, have not been fully performed since Korea had not experienced many destructive earthquakes in the past. However, due to more than 1200 earthquakes with low or moderate intensity in the off-coastal and inland of Korea during the past 20 years, and due to the recent moderate earthquakes in Korea, such as the 2016 Gyeongju Earthquake with M=5.8 and the 2017 Pohang Earthquake with M=5.4, the importance of the future earthquake preparedness measures is highly recognized in Korea. The main objective of this study is to provide the basic information regarding seismic capacities of existing low-rise reinforced concrete buildings in Korea. In this paper, seismic capacities of 14 existing low-rise reinforced concrete public buildings in Korea are evaluated based on the Japanese Standard for Evaluation of Seismic Capacity of Existing Reinforced Concrete Buildings. Seismic capacities between existing buildings in Korea and those in Japan is compared, and the relationship of seismic vulnerability of Korean buildings and Japanese buildings damaged due to severe earthquakes are also discussed. Results indicated that Korean existing low-rise reinforced concrete buildings have a narrow distribution of seismic capacities and they are relatively lower than Japanese buildings, and are also expected to have severe damage under the earthquake intensity level experienced in Japan. It should be noted from the research results that the high ductility in Korean existing low-rise buildings obtained from the Japanese Standard may be overestimated, because most buildings investigated herein have the hoop spacing wider than 30 cm. In the future, the modification of strength and ductility indices in the Japanese Standard to propose the seismic capacity evaluation method of Korean buildings is most needed.

• Composites Research
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• v.30 no.6
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• pp.331-337
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• 2017

The composite lattice structures have advantages of high specific stiffness and strength and are mainly applied to the structures of launch vehicles that carry the compressive load. However, since these structures are manufactured by filament winding technology, there are some defects and voids found in the knots. For these reasons, the stiffness and strength of the lattice structures have to be compared with finite element model for predicting design load. But, the full scale test is difficult because time and space are limited and the shape of structure is complex, and hence the simple and reliable test methods for examination of stiffness are needed. In this paper, subelements of composite lattice structures were prepared and compressive and bending test were conducted for examination of stiffness of helical and hoop rib. Test methods for subelements of composite lattice structures that has curved and twisted shape were supposed and compared with finite element analysis results.