• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.99-111
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• 1999

The object of this study is to get the superior double hull structure to its crashworthiness against collision comparing absorbed energy capacities of its various types with each other, varying material properties, collision positions and velocities, and structural arrangements such as double hull width, web and stringer spaces, etc. Local absorbed energy capacities, failure behaviors and damage extents of their members are also considered during collision in addition to the estimations of their global ones. This paper describes a series of numerical simulations of collisions between DWT 45,000 oil tanker(struck ship) and DWT 10,500 rigid one(striking ships) using Hydrocode LS/DYNA3D. Collisions are assumed to occur at the middle of struck ship with striking one moving at right angle to its centerline. The following remarks were obtained through this study: More flexible the double hull structure is, much superior its crashworthiness against collision is. The increment of double hull width does not give much influence than other factors do. The exact use of material property such as failure strain is also important on the numerical simulation of collision.

• Journal of Ship and Ocean Technology
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• v.5 no.4
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• pp.19-28
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• 2001

A comparative study of the new flexible double hull structure is presented as a collision energy absorbing system, which is constructed with mixed stringers comprising slant and straight stringers for the double hull tanker, The dimension and disposition of this mixed stringers are selected to give the maximum absorbing energy. From the viewpoint of collision energy absorbing efficiency, this structural system is compared with three other types of the double hull constructions with trapezoidal stiffener, stringer type and standard type of VLCC, 310K DWT, Based on the constant hull weight, the proposed double hull structure with mixed stringers shows a improved crashworthiness as the results.

• Journal of Ocean Engineering and Technology
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• v.25 no.3
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• pp.1-10
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• 2011

This paper estimates the residual longitudinal strength of a damaged double hull VLCC (Very Large Crude Carrier) under combined vertical and horizontal bending moments using Smith's method. The damage estimated in this study occurred due to collision or grounding accidents. The effects of the randomness of the yield stress, plate thickness, extent of damage, and the combination of these three parameters on the ultimate hull girder strength were investigated. Random variables were generated by a Monte Carlo simulation and applied to the double hull VLCC described by the ISSC (International Ship and Offshore Structures Congress) 2000 report.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.147-148
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• 2008

• Journal of Ship and Ocean Technology
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• v.3 no.1
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• pp.12-26
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• 1999

A new concept of collision energy absorbing system for ;he New Oil-tankers with Advanced Double Hull Structure(NOAHS and NOAHS II) are presented through the joint-research pro-gran between Inha and Hamburg-Harburg University. A comparative study on col vision resistance of these proposed side structures with standard double hull structure of 310K DWT class VLCC, is carried out. The fatigue investigation of structural detail parts is also included. It contains a comparative fatigue study based on pertinent regulations of Classification Societies.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.4
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• pp.398-408
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• 2009

Crude oil carriers or product oil carriers are confronted with sea pollution due to hull damage from various accidents. To reduce the oil spillage of tankers, IMO(International Maritime Organization) and OPA 90(Oil Pollution Act 1990) adopted the hull structures of double skin type. In this study, oil spillage test of the double skin tanker with 1/100 scaled model was carried out under damaged condition due to collision and grounding accidents. A new structural type of oil tanker was also tested with pipe and valve system arranged in double side and single bottom hulls. Their results were compared with that of conventional type double hull on the view point of ship safety and oil spillage.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.3
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• pp.507-528
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• 2014

In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSR-H) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures.

• Journal of Ocean Engineering and Technology
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• v.34 no.2
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• pp.97-109
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• 2020

In this study, ultimate strength characteristics of clamped sandwich panels with metal faces and an elastic isotropic core under combined in-plane compression and lateral pressure loads are investigated to verify the applicability of the ultimate strength design formula for ship structures. Alternative elastomer-cored steel sandwich panels are selected instead of the conventional bottom stiffened panels for a Suezmax-class tanker and then the ultimate strength characteristics of the selected sandwich panels are examined by using nonlinear finite element analysis. The change in the ultimate strength characteristics due to the change in the thickness of the face plate and core as well as the amplitude of lateral pressure are summarized and compared with the results obtained by using the ultimate strength design formula and nonlinear finite element analysis. The insights and conclusions developed in the present study will be useful for the design and development of applications for sandwich panels in double hull tanker structures.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.3
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• pp.265-274
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• 2015

International organizations and classification societies established rules and regulations to which shipbuilders and ship operators should comply during design, construction, even operation keeping from hazard to life of crews and ocean environment. Hence, rules and regulations could be guidelines for design and construction of ship sometimes. In practical wise, ship structure designers be predisposed to design lightest and easy-to-product structures which satisfy rules and regulations. Therefore, changes of rules and regulations are remarkably important issue to related industries. In 2006, IACS established and released Common Structural Rules for Bulk Carrier and Common Structural Rules for Double Hull Oil Tanker. These CSRs are consolidated and unified rules of class society's rules. But these two rules are different from each other. IACS has plan to release unified rule of two ship type called Harmonized Common Structural Rule for Bulk Carriers and Oil Tankers. This new rule will be effective from July 2015. Hence, bulk carrier and double hull oil tanker whose contract date is on and thereafter July 2015 should be complied with CSR-H. Therefore, it is highly important to be aware of consequences and cause of consequences with respect to CSR-H. The object of this research is to compare requirements of structure scantling in way of midship area for selected target ship according to CSRs and CSR-H and to analysis cause of deviation between two rules.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.71-76
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• 2004

To deal with ship collision or grounding, double hull structure has been applied to ships carrying dangerous cargoes. Studies about ability of double hull structure to absorb collision energy and determining fracture state are still under researching. In this study, commercial analysis code, LS-DYNA3D, is used to analyze collision strength of ships in various scenarios. 46K Chemical／Product Carrier is used as analysis subject ship. Study about Energy-Indentation and Force-Indentation is conducted under conditions that weight and collision velocity are changed. Results of this study are very helpful to make mechanism of collision accident clear and to supply useful information about collision strength criteria.