• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.46-49
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• 2015

Common Structural Rules (CSR) about bulk carriers and double-hull oil tankers of International Association of Classification Societies (IACS) has been applied to ships contracted for construction since April 2006. By unifying each society's rules, the difference of opinion in the between shipyard and ship owners, classification was reduced, and CSR has been evaluated by rules the safety structure more enhanced. However, The CSR about the bulk carriers and double hull oil tankers, important design content standards, such as the local scantling calculation, static/dynamic load case and corrosion margin and etc., are different. Therefore in order to combine the CSR, the Harmonized CSR for bulk carriers and double hull oil tankers (H-CSR) was issued on 1, January, 2014, and will be apply to ships contracted for construction after 1st July 2015. It is necessary to verify the H-CSR to optimize the structural arrangement because effective date is not far off. In this study, we compared the impact by rule change for the hull girder shear strength of bulk carriers between CSR and H-CSR in respect of the yielding and buckling strength.

• 대한조선학회논문집
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• 제53권3호
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• pp.188-194
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• 2016

Accurate estimation of shear flows in thin-walled beam section is the key issue to evaluate shear stress distribution of ship hull transverse section under the shear forces acting on hull girder. It is regarded that the method using the warping functions obtained by finite element formulation is the state of the art of this field. Recently, however, IACS took effect the new version of CSR in which direct calculation process of shear flow was suggested. In the direct calculation process, shear flow of ship hull section can be obtained by the addition of determinate and indeterminate shear flows calculated respectively. So, in this paper, the shear flow evaluation codes based on the process proposed by IACS CSR and warping function based method were developed respectively. The calculated results of shear flows for the several examples of ship sections were compared with each other and considered in detail.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.99-106
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• 2007

The IACS Common Structural Rules are to be applied for double hull tanker of more than 150m length with contracted after 1 April 2006. The objectives of the rules are to make more robust, safer ship and to ensure transparency of the technical background. In compliance of CSR, we had carried out prescriptive rules scantling determination and 3-D hold FE analysis of AFRAMAX TANKER. Prescriptive rules scantling determines the minimum required scantling, hull-girder longitudinal bending and shear strength, hull girder ultimate strength, local strength of plate and stiffener, strength of primary supporting member and fatigue assessment of the longitudinal stiffener end connections to the transverse bulkhead. 3-D hold FE analysis assesses the structural adequacy of the vessel's primary hull structure and major supporting members using yielding and buckling failure modes. So we could verify the strength assessment of AFRAMAX TANKER applied CSR.

• 수산해양기술연구
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• 제21권1호
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• pp.67-74
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• 1985

본 논문에서 얻은 결과를 요약하면 다음과 같다. 1) slamming 충격력에 의한 선각의 굽힘 모우멘트와 전단력의 계산은 본 논문의 이론 전개방법에 의해 구하는 것이 Antonides의 적용 방법보다 더 타당하다고 생각된다. 2) 수치계산 예에서 보면 선체 중앙단면에서 가장 큰 sagging moment가 발생하며 Antonides의 결과치 보다 3~5%정도 더 크게 나타났다. 3) 기준진동형의 중첩항 수는 주어진 문제의 특성 및 요구되는 정도에 따라 결정되어야 하므로 고차 진동형에 대한 실측치와 이론치의 비교 분석이 선행되어야 한다고 생각된다.

• 대한조선학회논문집
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• 제36권2호
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• pp.105-113
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• 1999

본 논문에서는 선체 단면의 St'Venant 비틂강성은 물론 굽힘-비틂 강성과 전단-비틂 강성 및 선체 개단면과 폐단면 연결부에서의 변위와 단면력의 연속조건을 고려한 보유추이론을 적용하여 수평 비틂 거동의 연성도가 크고, 비틂에 대해 유연한 선체 거더의 수평 비틂 연성 고유진동 감도해석방법을 제시하였다. 제시된 방법을 토대로 대형 컨테이너 운반선의 적화상태 변경시의 고유진동수를 감도해석 결과를 이용하여 추정한 결과는 통상적 재해석 결과와 비교하여 오차 1%이내의 매우 양호한 부합성을 나타내었다. 아울러, 수평거동과 비틂거동의 연성도가 큰 선박의 경우 선체 중량 중심이 형 깊이의 10%까지 변화할 경우에 고유진동수가 최대 8%까지 변화함을 확인하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.443-448
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• 2014

Recently, car-ferry passenger ships of navigating the coast area in the inside of our country are on an increasing trend of main engine power and the height of upper structure, which is increased to ship's speed and loading of large vehicles. The most ship with high-speed main engine is happened to excessive vibration by propeller induced excitation force on account of connecting the vibration of hull's girder and the upper structure by decreasing the shear stiffness and natural frequency for increasing the height of passenger deck. In this paper, By exchanging the propeller of alteration the number of blades, it could be keep to ship's speed and it's decreased the vibration of hull part that is located passenger deck on the upper deck, which is identified by countermeasure of protection against vibration to procure the safety ship's navigation through measuring the vibration of hull structure.

• 한국해양공학회지
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• 제6권2호
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• pp.103-112
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• 1992

The calculation method which takes into account the shear lag effects on the ultimate transverse bending moment of a SWATH(Small Waterplane Area Twin Hull) ship has been developed. In case of the ultimate bending strength analysis of conventional monohull ships and general box girder structures, the hypothesis that plane section remains plane after bending can be employed but not in the case of the structures having wide flange. For the ultimate bending strength analysis of such structures, a new method which can take into account the effect of shear lag on the ultimate bending strength has been developed by adopting more reasonable assumption that warping distortion of the section takes place inthe same way as the actual stress distribution. Finally, the proposed method has been applied to a a SWATH cross deck structure.

• 한국해양공학회지
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• 제22권5호
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• pp.132-137
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• 2008

Ship structures are subject to severe environmental loads causing appreciable hull girder bending which in turn affects the piping system attached to the main hull in the form of a displacement load. While this load may cause failure in the pipes, loops have been widely adopted as a means of preventing this failure, with the idea that they may lower the stress level in a pipe by absorbing some portion of the displacement load. But since such loops also have some negative effects, such as causing extra manufacturing cost, deteriorating the function of the pipe, and occupying extra space, the number and dimensions of the loops adopted need to be minimized. This research developed design formulas for pipe loops, modeling them as frames composed of beam elements, where not only bending but also shear deflection is taken into account. The accuracy of the proposed design formulas was verified by comparing two results respectively obtained by the proposed formulas and MSC/NASTRAN. The paper concludes with a sample example showing the efficiency of the proposed formulas.

• 수산해양기술연구
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• 제27권3호
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• pp.193-210
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• 1991

For the deckhouse or superstructure, attention is directed to the reduction of vibration from a human susceptibility point of view. The two basic requirements for obtaining a low vibration level in the accommodation are to ensure that excitation forces from propeller and/or main engine are small and to avoid resonance excitation of the hull and superstructure. In recent years increased attention has been directed towards the problems of vibration and noise in deckhouse, which have caused major problems with regard to the environmental quality in the living quarters for crews. Accordingly, in this paper, the characteristic of the vibration of deckhouse of fishing boat, of which the length/height ratio is also relatively high, are studied systematically with regard to the shape and modelling of deckhouse based on finite element method of 1-dimensional, 2-dimensional and 3-dimensional model. This study is divided into 4-part. 1st part is the global deckhouse vibration, 2nd part is the local deckhouse vibration, 3rd part consists of the estimation for stiffness of foundational support and 4th part is the application to TUNA LONG LINER of 416 ton class. For the global vibration analysis, the severity of the vibration depends on the longitudinal shear and bending stiffness of the deckhouse, on the vertical deckhouse support(fore, aft and sides). However, even if the design is technically sound, vibration problems may arise due to vertical or longitudinal hull girder or afterbody resonances. Author applied the method of this study to the analysis of, deep-sea fishing vessel of G.T. 416 ton class with relatively low height and long deckhouse, and investigated the vibrational characteristic of the fishing vessel with earlier structural feature. According to this investigation, the vibration, response of above vessel was confirmed of which main hull and deckhouse behave as one body. It is at the bottom of vibrational trouble which a accommodation part of the fishing vessel is raised, that is the local vibration for side wall, fore-aft wall and deck plate of deckhouse rather than thief fect of fore-aft vibration of deckhouse for above fishing vessel. and the resonance of main hull, deckhouse and driving system such as the main engine, propeller in exciting source is mainly brought up as the trouble.

• 대한조선학회지
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• 제27권1호
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• pp.35-44
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• 1990

근년에 이르러 에너지 절약형선(節約型船) 개발이 촉진됨에 따라 디이젤엔진이 대구경(大口徑) 장행정(長行程) 소수(小數)실린더 저회전수화(低回轉數化)함으로써 불균형(不均衡)모멘트가 커져서 특히 중형선(中型船)에 대해 저진동수영역(低振動數領域)의 선체진동(船體振動) 방진설계(防振設計)가 주요과제로 대두되고 있다. 자동차운반선(自動車運搬船)의 경우 구조적(構造的) 특성(特性) 및 선형기하학적(船型幾何學的)인 특성(特性)이 일반상선(一般商船)과는 매우 다르다. 본 논문에서는 선체상하진동(船體上下振動), 선체수평(船體水平) 비틂연성진동(聯成振動)에 대하여 보유추(類推)이론에 의거한 해석방법의 정립을 위하여 전기 특성을 고려한 적정한 모델링방법, 부가수질량(附加水質量) 및 동 중심(中心), 부가수질량(附加水質量) 극관성(極慣性) 모멘트, 단면(斷面)의 전단계수(剪斷係數) 등의 적정한 산정방법, 수평(水平) 비틂거동(擧動)의 연성도(聯成度), modal해석(解析) 즉 mode중 첩법에 의한 강제진동응답(强制振動應答)의 계산 등에 관하여 실선(實船)에 대한 수치실험적(數値實驗的) 계산예(計算例)를 통해 일련의 고찰을 거쳐 합리적인 해석방법을 제시하였다.