• Elastomers and Composites
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• 제52권4호
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• pp.280-286
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• 2017

The mechanical and dynamic properties according to the content of filler, plasticizer, and crosslinking agent of rubber composites for Lipseal were measured in this study. The mechanical properties of the composite including the silane coupling agent and silica were found to be superior to those of the composite containing carbon black. It was found that the rebound resilience characteristics were influenced by the crosslink density of sulfur rather than the filler or plasticizer. In the case of recovery, it was confirmed that the elastic restoring force improved in the compression deformation condition and recovery increased as the crosslinking density increased. The rubber composite for Lipseal of this study is expected to improve the manufacturing technology of the rubber composite which can implement the optimum function for recognizing the performance such as oil resistance, durability and compression set.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권2호
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• pp.57-67
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• 2010

Experimental investigations were carried out on an Axi-symmetric Body Model fitted with Pump-jet Propulsor (PJP) in the Cavitation Tunnel at Naval Science and Technological Laboratory (NSTL). The tests were intended for evaluating the propulsion characteristics of the body and propulsor. The self propulsion point of the model for two configurations was determined after finding the corrections for tunnel blockage effects and differences in model length at zero trim. The results were found to match closely with the towing tank results. The rotor and stator torques also matched closely over full range of experiment. Further experiments were carried out on the body at $4.5^{\circ}$ angle of trim to investigate the propulsive performance and assess the operational difficulties in the sea. The results indicated an increase in resistance and decrease in rotor thrust; but the balance of torques between the rotor and stator was undisturbed, causing no concern to vehicle roll.

• 대한조선학회논문집
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• 제44권4호
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• pp.425-438
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• 2007

In this paper, unsettled technical controversies concerning about fatigue strength analysis for FPSO, one of the representative floaters, associated with welding types, screening methods, fabrication tolerances, corrosion margins and Morison loads are described based on yard practices. Basic theory for stochastic fatigue analysis is introduced as detail as possible. In order to resolve large parts of the controversies, a new fully stochastic fatigue analysis program for FPSO is developed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1697-1702
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• 2008

The objective of the review is to introduce the evaluation method of welding joint designs by using forces extracted from FE models. This evaluation method is currently being used for the Southeastern Pennsylvania Transportation Authority (SEPTA) project in the United States by request of the customer Engineer. The evaluation method was applied to critical joints connected by Fillet or Partial Joint Penetration (PJP) welds in car body structure for SEPTA project. The additional manual analysis is required based on the fact that Technical Specification in the United States requires the Contractor to apply Complete Joint Penetration (CJP) welds to all structural connections in Car body. However, in the car body design for Septa project there are some areas where CJP welds are not applied due to structural and manufacturing problems.

• 한국강구조학회 논문집
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• 제25권4호
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• pp.431-440
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• 2013

본 연구에서는 HSA800 후판 강재에 적합한 용접재를 선정하고자 표준인장실험을 수행하였다. 본 연구 수행 당시 HSA800 강재에 적용가능한 용접재로 GMAW 용접재(외국산)와 FCAW 용접재(국내산) 두 가지가 추천되어 이들을 사용하였다. 맞댐용접상세와 루트간격을 주요 실험변수로하여 표준인장실험을 통해 용접부의 성능을 평가하였다. 강도에 대한 설계요구조건은 두 용접재 모두 만족하였으나 연성능력 측면에서 GMAW 용접재 보다는 FCAW 용접재가 일관되고 우수한 거동을 보임이 실험적으로 확인되었다. 특히 GMAW 용접재는 용접효율과 작업성의 문제로 현장에서의 상향용접이 어려운 것으로 파악되었다. 같은 완전용입용접이라도 Single bevel보다는 V-groove가 안정적인 구조거동을 보이는 것으로 나타났다. 또한 현행 용접기준의 표준루트 간격을 벗어날 경우 용착의 어려움으로 비정상 파단면이 형성되고 접합성능도 저하됨이 확인되었다. 부분용입용접 접합부의 실험결과에 의할 때 현행 AISC 기준의 부분용입용접부 강도규정은 매우 보수적임이 확인되었다.