• 제목/요약/키워드: tie-down system

검색결과 9건 처리시간 0.026초

The structural safety assessment of a tie-down system on a tension leg platform during hurricane events

  • Yang, Chan K.;Kim, M.H.
    • Ocean Systems Engineering
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    • 제1권4호
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    • pp.263-283
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    • 2011
  • The performance of a rig tie-down system on a TLP (Tension Leg Platform) is investigated for 10-year, 100-year, and 1000-year hurricane environments. The inertia loading on the derrick is obtained from the three-hour time histories of the platform motions and accelerations, and the dynamic wind forces as well as the time-dependent heel-induced gravitational forces are also applied. Then, the connection loads between the derrick and its substructure as well as the substructure and deck are obtained to assess the safety of the tie-down system. Both linear and nonlinear inertia loads on the derrick are included. The resultant external forces are subsequently used to calculate the loads on the tie-down clamps at every time step with the assumption of rigid derrick. The exact dynamic equations including nonlinear terms are used with all the linear and second-order wave forces considering that some dynamic contributions, such as rotational inertia, centripetal forces, and the nonlinear excitations, have not been accounted for in the conventional engineering practices. From the numerical simulations, it is seen that the contributions of the second-order sum-frequency (or springing) accelerations can be appreciable in certain hurricane conditions. Finally, the maximum reaction loads on the clamps are obtained and used to check the possibility of slip, shear, and tensile failure of the tie-down system for any given environment.

KUH 사례를 통한 헬기 비행전 수락시험 수행 방안 (A Way to Perform a Helicopter PFAT by KUH Case Study)

  • 이상목;황정선
    • 한국항공우주학회지
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    • 제41권12호
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    • pp.994-1001
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    • 2013
  • 헬기의 개발 과정은 설계, 제작 및 시험평가로 구분될 수 있으며, 시험평가는 구성품 시험, Rig 시험, 체계 지상시험 및 비행시험의 순서로 단계적으로 수행된다. 지상시험이 종료되고 최초 비행에 앞서, 비행 안전성을 담보하기 위해 미군사규격은 50시간 비행전 수락시험을 요구하고 있다. 비행전 수락시험은 헬기를 지상결박하여 가혹한 하중을 부과하는 시험으로서, 이의 수행을 위해서는 헬기 시제기와 유사한 별도의 지상 시험 시제기가 필요하며, 많은 비용과 기간이 소요되는 시험이다. KUH의 경우 국내 개발 환경을 고려하여 미군사규격의 요구도를 변형 후 수행하였으며, 본 논문은 KUH 비행전 수락시험의 절차 및 결과를 통하여 헬기 개발 환경에 따른 적절한 비행전 수락시험 수행 방안을 제시하고자 한다.

가스질화처리 적용을 통한 스마트무인기 머레이징강 로터허브 부품 품질개선 (Quality Improvement of Smart UAV Rotor-Hub Part Through Gas Nitriding of Maraging Steel)

  • 이명규;최성욱;김재무
    • 항공우주시스템공학회지
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    • 제8권2호
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    • pp.33-39
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    • 2014
  • Feathering spindle is one of the critical parts of the rotor system in the Smart Unmanned Aerial Vehicle(SUAV) that it was manufactured with special material, Maraging C300. During the initial ground and tie-down flight tests of the SUAV, surface of the feathering spindle contacting to the needle-roller bearings showed excessive wear and dent due to high vibrating loads transferred from the rotating blades. Gas nitriding process was applied to the bearing contact surface of the feathering spindle to increase surface hardness so as to improve the surface defects. This paper briefly presents the gas nitriding process adopted and the spindle quality improvements including wear and corrosion resistance.

마르코프 연쇄 몬테 카를로 샘플링과 부분집합 시뮬레이션을 사용한 컨테이너 크레인 계류 시스템의 신뢰성 해석 (Reliability Analysis of Stowage System of Container Crane using Subset Simulation with Markov Chain Monte Carlo Sampling)

  • 박원석;옥승용
    • 한국안전학회지
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    • 제32권3호
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    • pp.54-59
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    • 2017
  • This paper presents an efficient finite analysis model and a simulation-based reliability analysis method for stowage device system failure of a container crane with respect to lateral load. A quasi-static analysis model is introduced to simulate the nonlinear resistance characteristics and failure of tie-down and stowage pin, which are the main structural stowage devices of a crane. As a reliability analysis method, a subset simulation method is applied considering the uncertainties of later load and mechanical characteristic parameters of stowage devices. An efficient Markov chain Monte Carlo (MCMC) method is applied to sample random variables. Analysis result shows that the proposed model is able to estimate the probability of failure of crane system effectively which cannot be calculated practically by crude Monte Carlo simulation method.

수치해석을 이용한 연약지반에 시공된 스마트 앵커의 거동 분석 (Numerical Analysis of Smart Anchors in Soft Clay by)

  • 김낙경;김성규;강병철;김정열
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.964-968
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    • 2010
  • Ground anchor, commonly referred to as tiebacks or tie-down, is essentially steel elements secured in the ground by cement grout. They are used to provide either lateral or vertical support for various engineered structures, and are effective in all types of soil and rock. However, ground anchor can not be used in soft clay because anchor resistance would not be guaranteed. In this paper, conceptual introduction of the Smart Anchor is presented. The Smart Anchor is a kind of friction type anchor, the load is diffused and applied to the various parts of the distributed bond length, having less impact on the grout strength, and being able to secure necessary anchoring force in relatively soft grounds. This study shows a numerical study of predicting the load transfer of The Smart Anchor in soft clay. A beam-column analysis was performed by a elastic-plastic P-y curves in soft clay.

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향화인의 조선 정착 사례 연구 - 여진 향화인을 중심으로 - (Some Instances of Manchurian Naturalization and Settlement in Choson Dynasty)

  • 원창애
    • 동양고전연구
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    • 제37호
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    • pp.33-61
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    • 2009
  • 고려 말에 동북면에 들어와서 거주하던 토착여진과 요동 지방 내륙에서 남하하여 두만강 유역 부근에 자리잡은 알타리 올량합 올적합 등의 여진족이 향화하였다. 향화한 여진인에게 경제적 사회적 정치적 우대 정책이 시행되었다. 특히 향화인에게 과거 응시를 허락한 것은 이들을 조선의 백성으로 인정한 단적인 예이며, 이들이 과거를 통해서 자신들의 신분을 상승시킬 수 있는 길을 열어놓았다. 향화인 가운데 성공적으로 조선에 정착하여 양반으로 성장한 사례가 있는데, 청해 이씨와 전주 주씨이다. 청해 이씨는 여진의 대추장으로서 관하민도 500호나 되었으며, 개국공신 회군공신 배향공신으로서 조정에서 경제적 사회적 정치적 혜택을 충분히 받았다. 게다가 이지란의 아들 이화영 역시 공신으로서 그의 정치적 입지를 굳혀갔고, 종친과의 혼인으로 왕실과 관계를 돈독히 하였다. 이지란과 이화영이 마련한 기반 위에서 양반 가문으로서 계속 성장된 것은 이화영의 아들 이효양(李孝讓)과 이효강(李孝綱) 집안이다. 이 두 가문에서 배출된 과거 급제자는 문과 7명, 무과 15명, 생원 진사시 16명 등이다. 청해 이씨의 주된 거주지는 서울과 경기 지역이었으며, 일부 함경도 지역에도 남아있었다. 전주 주씨는 함흥에 같이 정착했던 주만(朱萬)은 개국원종공신에 책봉되었고, 주인(朱仁)은 중앙으로부터 서반직을 제수받았다. 전주 주씨는 함흥에 토착하여 재지 세력으로 성장되었다. 16세기부터 문과 급제자가 배출되기 시작하여 17세기 이후로 문과 급제자 22명, 생원 진사시 입격자 40명을 배출한 문인 가문으로 성장하였다. 전주 주씨의 관직 진출을 보더라도 서북 인사에게 통청되기 어려웠던 언관직 진출이 많았다. 전주 주씨는 함흥을 중심으로 재지 기반을 확고히 하고 언관과 같은 청직에 진출되면서 함경도의 명문 성관으로 부상되었다.

근대이후 여성 생활한복의 특징 및 변천 (Characteristic and Transition of woman's Saeng-Hwal-Han-Bok after Modern Korea)

  • 김미진;김혜영;조우현
    • 한국의상디자인학회지
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    • 제7권2호
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    • pp.137-158
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    • 2005
  • Modernization of Korea had begun with the reformation of the Kab-o Reform in 1894, which the government had designed after the protectorate treaty with Japan in 1876. It had affected drastic changes on the formation and framework of a Han-bok by government and the main changes is found in creating new style of Gae-ryang Han-bok. During 1980's, the peoples were interested in traditional cultural heritage, and 'the campaign of wearing Woo-Ri Ot' prevailed in Korea to instill the radical sprit of Korean. A Han-bok, which was made at this time, has called a Saeng-hwal Han-bok. The purposes of this study are to defue the the words that are Han-bok, Gae-ryang Han-bok and Saeng-hwal Han-bok of meaning and characteristic based on the previous studies and historical materials and present a unified and historical opinion about Han-bok to the academic world and industry of Han-bok by the consideration. Han-bok is a traditional costume with a long skirt and long breast-tie based on the later Cho-sun and is emphasized a virtue and manner on it. Gae-ryang Han-bok is an improved Han-bok that is include with a Tong-Chima and Jeogori for making a movement and function better. Saeng-hwal Han-bok is originated by the movement of wearing Woo-ri Ot in 1984, is interpreted the traditional Korean beauty from the modem view and is a practice Han-bok for popularizing intodaily life. After investigating the 33 of previous studies, the characteristics and transitions of Han-bok are followed. First, the reason of fail about the reform of dress is a loss of traditional beauty. Second, the yes or no of the establishment of law about the reform of dress, it influenced on a reforming or wearing speed of costume. Third, after 8.15, a modem girl and girl student can not impact on a system of Korean women anymore because, the number of the group that means a high educated and active woman, was growing. So, the elevation of women's education matured the system of Korean women's costume. forth, western style clothes are popularized after the Korean War and it is set down in the system of Korean women's dress.

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고려(高麗) 금동탑(金銅塔)을 통해 본 법주사(法主寺) 팔상전(捌相殿)의 구조형식계통(構造形式系統) (The Structural Lineage of Palsangjeon in Pubjoo Temple Analyzed through Gilt-bronze Pagoda in the Koryo Period)

  • 김경표
    • 건축역사연구
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    • 제14권1호
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    • pp.89-105
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    • 2005
  • The central aim of this thesis is to see if the structure of Palsangjeon(捌相殿) in Pubjoo Temple(法住寺), a five sto wooden pagoda in Chosen(朝鮮) Dynasty, was handed down from the ancient and middle ages. This study was performed through an analysis of Gilt-Bronze Pagoda built in Koryo(高麗) period. In other words, it is aimed at analyzing which lineage the structure of Palsangjeonbelongs to as a wooden pagoda. In analyzing the structure of Palsangjeon, I attempted to find out its source from the remains of Koryo period prior to the Chosen Dynasty. Examples are the Gilt-Bronze Pagoda, built during the Koryo period. I have also examined its relationship with other existing wooden pagodas and remains. The analysis of Palsangjeon, a five story wooden pagoda in Chosen Dynasty, focuses on the following: First, I explored the possibilities of whether the structure of Palsangjeon was newly invented in Chosen Dynasty, or if it had been derived from the wooden pagodas in the Koryo period. Secondly, I tried to find out if the stable vertical planes, with a great successive diminution ratio, were derived from the middle age, i.e. Koryo period. The results of the study of Palsangjeon through Gilt-Bronze Pagoda analysis are as follows: 1. The structure of Gilt-Bronze Pagoda, a wooden pagoda from the Koryo period, is roughly classified into the accumulation type, using pipe pillars, and the one story type using whole pillars. In the accumulation type, stories are connected in either a flat format or an intervening format. The Gilt-Bronze Pagoda is mainly composed of pipe pillars, with some whole pillars. However, the central pillar was omitted in the building structure. Generally, the upper and lower stories are connected by pipe pillars in a crutch format. All the pillars, whether they are pipe pillars or whole pillars, used Naiten(內轉) technology. The Eave supporter has the Haang type(下昻) and the Muhaang type(無下昻). In most cases, high balustrades are furnished, but few tables of high balustrades have been found. The slanting roof formats have been handed down from Paekche(百濟), Silla(新羅), or Koryo(高麗). However, the structure of the octagon is assumed to be derived from Koguryo(高句麗). The structure of the Gilt-Bronze Pagoda from the Koryo period is mainly composed of accumulated flat squares, with some spire types. intervening format, the structure of Palsangjeon used whole pillars in a half story format in which upper level side pillars are installed on the lower level tie beam. From the Bronze Pagoda from the Koryo period, we can assume that the half story format of wooden pagodas that has stable vertical planes with a great successive diminution ratio was created during the mid-Koryo period at the latest and had been idly developed by the time of the Chosen Dynasty. 3. The whole pillars in Palsangjeon are also found in Gilt-Bronze Pagodas from the Koryo period. Hence, all of the pillars in Palsangjeon seem to have been handed down from the ancient construction technology. They were also used in the construction of wooden pagodas from the Koryo period. Therefore, it is assumed that Palsangjeon was constructed using the construction technology of the Chosen Dynasty that had been developed from the wooden pagoda construction technology of the Koryo period. The stable vertical planes with a great successive diminution ratio in Palsangjeon are derived from ancient Korean wooden pagodas, which have developed into indigenous Korean wooden pagodas with fairly stable vertical planes and a great design, in the half story format of Koryo and Chosen Dynasty. Therefore, it is assumed that the structure of Palsangjeon has a systematic relationship with traditional Korean wooden pagodas and is one of the indigenous Korean wooden pagoda structures. 4. In China, the intervening format has been mainly used between stories in multi-story architecture since the ancient days. At the same time, the flat format as also used in ancient and middle ages. However, the flat format was replaced by whole pillars during the Ming(明) and Manchu(淸) Dynasties, in favor of simple and compact construction. The half-story format, in which upper level side pillars are installed on tie beams, has been found in some cases, but it doesn't seem to have been the primary construction technology. Few traces of the half-story format have been found in multi-story architecture in Japan, and it has not been used as a general construction format. By contrast, the half-story format, which seems to have been derived from the Koryo period, was used as a general construction format in multi-story architecture of the Chosen Dynasty. The construction technology of multi-story architecture is related to that of multi-story wooden pagodas, but they have different production technologies. It seems that the structure of Palsangjeon did not just adopt the construction technology of multi-story architecture in the Chosen Dynasty, but it was developed from wooden pagodas in the Koryo period, including the Gilt-Bronze Pagoda. 5. Since the ancient days, most Chinese and Japanese wooden pagodas have adopted an accumulation type of structure using pipe pillars, with accumulated pointed towers. On the other hand, though most Korean wooden pagodas have also adopted an accumulation type of structure from the ancientdays, one story type using whole pillars was created in the Koryo and Chosen Dynasties. The wooden pagoda structure of Palsangjeon, with stable vertical planes in a half story format, is a unique Korean construction technology, different from the construction technologies of Chinese and Japanese wooden pagodas. This thesis clearly determined the structural characteristics of Palsangjeon. However, various remains have yet to be analyzed in depth, to establish an accurate construction technology system. In the beginning of this thesis, I had difficulty in precisely interpreting the internal structure of the Gilt-Bronze Pagoda from its appearance. However, in the process of study, the more serious problem was that there are few remains or ruins of multi-story architecture in ancient and the middle ages of Korea. Therefore, it is urgent to discover various remains in the future. This thesis succeeded in determining the structural characteristics of Palsangjeon. However, it fell short of clarifying the structural lineage of the stable vertical planes, although they show indigenous Korean architectural taste, representing the unique national emotion, and the construction format of multi-story wooden pagodas in Korea. I hope this is clarified in the future research.

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중국(中國) 연변지구(延邊地區) 조선족(朝鮮族)마을의 구성(構成) 룡정시 지신향 장재촌을 대상으로 (Tie Spatial Structure of Ch'ang-ts'ai-ts'un Village A Case Study on a Rural Village of Korean Immigrants in Yen-pien Area of China)

  • 이규성
    • 건축역사연구
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    • 제3권1호
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    • pp.83-99
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    • 1994
  • Ch'ang-Ts'al-Ts'un is a rural Village near Lung-jing City in Yen-pien Korean Autonomous Province of China. It was formed about 100 years ago by Korean Immigrants and has been developed maintaing the characteristics of traditional Korean architecture. Therefore investigating the spatial structure of this village is a meanigful work to confirm and explore one branch of Korean architecture. This study aims at analyzing the spatial structure of the village using direct data collected from the field work and indirect data from books and maps. The field work consists of on-the-site survey of the village layout, interviews of residents, observation notes and photography. Ch'ang-Ts'ai-Ts'un is located 360-370 m high above the sea level and at the side of a long valley. A river flows in the middle of the valley and relatively flat arable land exists at the both sides of the river. The location of the village related to the surrounding river and mountains suggests that the site of the village was chosen according to Feng-Shui, Chinese and Korean traditional architectural theory. The main direction of the house layouts is South-western. The village has been growing gradually until today. Therefore it is meaningful to make the village layout before Liberation(1946 A.D.) because the characteristics of Korean architecture prevailed more in that period. The area of the previous village is limited to the west side of the creek. New houses were later added to the east of the creek, forming a 'New Village'. Previously the village was composed of 3 small villages: Up, Middle and Down. Also the main access roads connecting the village with the neighboring villages were penetrating the village transversely. Presently the main access road comes to the village longitudinally from the main highway located in front of the village. The retrospective layout shows the existence of well-formed Territory, Places and Axes, thus suggesting a coherent Micro-cosmos. The boundary of imaginery territory perceived by present residents could be defined by linking conspicous outside places sorrounding the village such as Five-mountains, Front-mountain, Shin-dong village, Standing-rock, Rear-mountain and Myong-dong village. Inside the territory there are also the important places such as Bus-stop, Memorial tower of patriots, Road-maitenance building and the village itself. And inside it 5 transverse and 1 longitudinal axes exist in the form of river, roads and mountains. The perceived spatial structure of the village formed by Places, Axes and Territory is geometrical and well-balanced and suggests this village is fit for human settlement. The administrative area of the village is about 738 ha, 27 % of which is cultivated land and the rest is mountain area. Initially the village and surrounndings were covered with natural forest But the trees have been gradually cut down for building and warning houses, resulting in the present barren and artificial landscape with bare mountains and cultivated land. At present the area of the village occupied by houses is wedge-shaped, 600 m wide and 220 m deep in its maximum. The total area of the village is $122,175m^{2}$. The area and the rate of each sub-division arc as follow. 116 house-lots $91,465m^{2}$ (74.9 %) Land for public buildings and shops $2,980m^{2}$ (2.4 %) Roads $17,106m^{2}$ (14.0 %) Creek $1,356m^{2}$ (1.1 %) Vacant spaces and others $9,268m^{2}$ (7.6 %) TOTAL $122,175m^{2}$ (100.0 %) Each lot is fenced around with vertical wooden pannels 1.5-1.8 m high and each house is located to the backside of the lot. The open space of a lot is sub-divided into three areas using the same wooden fence: Front yard, Back yard and Access area. Front and back yards are generally used for crop-cultivation, the custom of which is rare in Korea. The number of lots is 116 and the average size of area is $694.7m^{2}$. Outdoor spaces in the village such as roads, vacant spaces, front yard of the cultural hall, front yard of shops and spacse around the creek are good 'behavioral settings' frequently used by residents for play, chatting, drinking and movie-watching. The road system of the village is net-shaped, having T-junctions in intersections. The road could be graded to 4 categories according to their functions: Access roads, Inner trunk roads, Connecting roads and Culs-de-sac. The total length of the road inside the village is 3,709 m and the average width is 4.6 m. The main direction of the road in the village is NNE-SSE and ESE-WNW, crossing with right angles. Conclusively, the spatial structure of Ch'ang-Ts'ai-Ts'un village consists of various components in different dimensions and these components form a coherent structure in each dimension. Therefore the village has a proper spatial structure meaningful and appropriate for human living.

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