• Title/Summary/Keyword: upper deck

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Characteristic of Buckling and Ultimate Strength of the Perforated Stiffened Plate (유공보강판의 좌굴 및 극한강도 특성에 관한 연구)

  • Park Joo-Shin;Ko Jae-Yong;Oh Kyoung-Gun
    • Journal of Navigation and Port Research
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    • v.30 no.6 s.112
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    • pp.439-446
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    • 2006
  • In ship structures many of the structural plates have cutouts, for example, at inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has a cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed In general, actual ship structure adopted reinforcement of stiffener around the cutout in order to preventing from buckling so it need to examine a buckling and ultimate strength behaviour considering a cutout because In many ship yards used class rule for calculating buckling strength but it is difficult to evaluate perforate stiffened plate with random size. In the present paper, we investigated several kinds of perforated stiffened model from actual ship and then was performed finite element series analysis varying the cutout ratio, web height, thickness and type of cross-section using commercial FEA program(ANSYS) under compressive load.

Development of Designed Formulae for Predicting Ultimate Strength of the Perforated Stiffened Plate subjected to Axial Compressive Loading (압축하중을 받는 유공보강판 구조의 최종강도 설계식 개발)

  • Park, Joo-Shin;Ko, Jae-Yong;Lee, Kyung-Hwan
    • Journal of Navigation and Port Research
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    • v.31 no.5 s.121
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    • pp.435-445
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    • 2007
  • Ship structures are thin-walled structures and lots of cutouts, for example, of inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed. In the present paper, we investigated several kinds of perforated stiffened model from actual ship structure and series of elasto-plastic large deflection analyses were performed to investigate into the influence of perforation on the buckling and ultimate strength of the perforated stiffened plate varying the cutout ratio, web height, thickness and type of cross-section by commercial FEA program(ANSYS). Closed-form formulas for predicting the ultimate strength of the perforated stiffened plate are empirically derived by curve fitting based on the Finite Element Analysis results. These formulas are used to evaluate the ultimate strength, which showed good correlation with FEM results. These results will be useful for evaluating the ultimate strength of the perforated stiffened plate in the preliminary design.

Dispersion Characteristics of Wave Forces on Interlocking Caisson Breakwaters by Cross Cables (크로스 케이블로 결속된 인터로킹 케이슨 방파제의 파력분산특성)

  • Seo, Ji Hye;Yi, Jin Hak;Park, Woo Sun;Won, Deck Hee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.5
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    • pp.315-323
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    • 2015
  • Damage level of coastal structures has been scaled up according to increase of wave height and duration of the storm due to the abnormal global climate change. So, the design criteria for new breakwaters is being intensified and structural strengthening is also conducted for the existing breakwaters. Recently, interlocking concept has been much attention to enhance the structural stability of the conventional caisson structure designed individually to resist waves. The interlocking caisson breakwater may be survival even if unusual high wave occurs because the maximum wave force may be reduced by phase lags among the wave forces acting on each caisson. In this study, the dispersion characteristics of wave forces using interlocking system that connect the upper part of caisson with cable in the normal direction of breakwater was investigated. A simplified linear model was developed for computational efficiency, in which the foundation and connection cables were modelled as linear springs, and caisson structures were assumed to be rigid. From numerical experiments, it can be found that the higher wave forces are transmitted through the cable as the angle of incident wave is larger, and the larger the stiffness of the interlocking cable makes larger wave dispersion effect.

Evaluation of Seismic Performance of Pile-supported Wharves with Batter Piles through Response Spectrum Analysis (응답스펙트럼해석을 통한 경사말뚝이 설치된 잔교식 안벽의 내진성능 평가)

  • Yun, Jung-Won;Han, Jin-Tae;Kim, JongKwan
    • Journal of the Korean Geotechnical Society
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    • v.37 no.12
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    • pp.57-71
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    • 2021
  • The pile-supported wharf is the port structure in which the upper deck is supported by piles or columns. By installing batter piles in this structure, horizontal load such as earthquake loads can be partially delivered as axial forces. The codes suggests using the response spectrum analysis as a preliminary design method for seismic design of pile-supported wharf, and suggests modeling the piles using virtual fixed points or soil spring methods for this analysis. Recently, several studies have been conducted on pile-supported wharves composed of vertical piles to derive a modeling method that appropriately simulates the dynamic response of structures during response spectrum analysis. However, studies related to the response spectrum analysis of pile-supported wharves with batter piles are insufficient so far. Therefore, this study performed the dynamic centrifuge model test and response spectrum analysis to evaluate the seismic performance according to the modeling method of pile-supported wharves with batter piles. As a result of test and analysis, it is confirmed that modeling using the Terzaghi (1955) constant of horizontal subgrade reaction (nh) most appropriately simulates the actual response in the case of the pile-supported wharf with batter piles.

"A Study on Hebrews Clothing in the Old Testament" - Especially on Hair Styles, Headgears, Footwear and Personal Ornaments - (구약성서(舊約聖書)에 나타난 히브리인의 복식(服飾) - 두식(頭飾), 신발 및 장신구(裝身具) 중심(中心)으로 -)

  • Park, Chan-Boo
    • Journal of the Korean Society of Costume
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    • v.10
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    • pp.63-80
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    • 1986
  • The Old Testament cotains mention of the history of creation and clothing in ancient Hebrew. This study dealt with Hebrew dress customs especially aimed at the manners of their hair styles, headgears, footwear and personal ornaments. References are Korean Revised Version, English King James Version and Revised Standard Version. There is little mention of hair styles and headgears in the Old Testament. Some sort of turban was worn by priests, and soldiers protected themselves with helmets, but most Israelitish men went bareheaded except on special occasions and often wear simple headbands. It was more common for women to use headwear of some type-turbans, scarves, and veils concealing the face. The veil was the distinctive female wearing apparel. All females, with the exception of maidservants and women in a low condition of life, wore a veil. It was the custom for women to wear a veil entirely covering their head in the public. Through most of the Old Testament periods long and thick hair was admired on men and women alike. The Hebrews were proud to have thick and abundant long hair, and they gave much attention to the care of their hair. The caring of hair was deeply related to their rituals. Nazirites never took a razor to their hair during his vow-days, but instead let it grow long, as an offering to God. Men would not cut their beards, but allow them to grow long. The Israelites' standard footwear was a pair of simple leather sandals. This was one of the items of clothing not highly prized. In a colloquial saying of the time, a pair of shoes signified something of small value, and to be barefoot except in times of mourning or on holy place, was a sign either of extreme poverty or humiliation, as in the case of war prisoners. Because precious stones were not mined in the Palestine-Syria region, Hebrews imported them from foreign country. They were consumer-to a large degree limited by their very modest standard of living-but not producers. Hebrews liked the precious stones and were motivated to acquire and wear jewels. Besides their use for adornment and as gifts, the precious or semiprecious stones were regarded by Jews of property. The Hebrews were not innovators in the field of decorative arts. The prohibition of the Law against making any "graven image" precluded the development of painting, sculpture, and other forms of representational art. Jewish men did not indulge in extravagances of dress, and there was little ornamentation among them. Men wore a signet ring on their right hand or sometimes suspended by a cord or chain around the neck. The necklaces, when worn by a male, also bore any symbol of his authority. Bracelets were extremely popular with both men and women, men usually preferring to wear them on their upper arms. The girdle was a very useful part of a man's clothing. It was used as a waist belt, or used to fasten a man's sword to his body, or served as a pouch in which to keep money and other things. Men often carried a cane or staff, which would be ornamented at the top. Among the women there was more apt to be ornamentation than among the men. Hebrew women liked to deck themselves with jewels, and ornamentation of the bride were specially luxurious and numerous. They wore rings on their fingers or On toes, ankle rings, earrings, nosering, necklace, bracelets. Their shapes were of cresent, waterdrops, scarab, insect, animal or plant. Sometimes those were used as amulets. They were made of ceramics, gold, silver, bronze, iron, and various precious stones which were mostly imported from Egypt and Sinai peninsular. Hebrews were given many religious regulations by Moses Law on their hair, headgears, sandals and ornamentation. Their clothing were deeply related with their customs especially with their religions and rituals. Hebrew religion was of monotheism and of revealed religion. Their religious leaders, the prophets who was inspired by God might need such many religious regulations to lead the idol oriented people to God through them.

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