Residual ultimate longitudinal strength – grounding damage index diagram of a corroded oil tanker hull structure

2013 ◽  
pp. 171-178
Author(s):  
D Kim ◽  
H Kim ◽  
X Zhang ◽  
J Paik ◽  
J Seo
Keyword(s):  
Damage Index ◽  
Hull Structure ◽  
Longitudinal Strength ◽  
Oil Tanker

Development of a Relationship Between Residual Ultimate Longitudinal Strength Versus Grounding Damage Index Diagram for Container Ships

2012 ◽  
Author(s):  
Do Kyun Kim ◽  
Han Byul Kim ◽  
Xiaoming Zhang ◽  
Preben Terndrup Pedersen ◽  
Min Soo Kim ◽  
...  
Keyword(s):  
Structural Damage ◽  
Damage Index ◽  
International Maritime Organization ◽  
Longitudinal Strength ◽  
Fire And Explosion ◽  
Damage Criteria

Various accidents such as grounding, collision, fire, and explosion commonly occur on operating ships. The structural damage caused by such accidents is often accompanied by casualties and serious pollution. Therefore, an accidental risk-based approach that is in line with the goal-based standard of the International Maritime Organization is being developed in the literature. In the present paper, the residual ultimate longitudinal strength versus grounding damage diagram (R-D diagram) for container ships is established as per the method of Paik et al. [1]. The proposed R-D diagram should be useful for defining acceptance damage criteria and making rapid salvage plans or rescue schemes for container ships that have sustained a grounding accident.

scholarly journals Oil Tanker Simplified Fatigue Assessment with Inspection and Repair Approach and Parameters

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ozgur Ozguc
Keyword(s):  
Fatigue Life ◽  
Life Assessment ◽  
Time To Failure ◽  
Maritime Industry ◽  
Safety Level ◽  
Fatigue Assessment ◽  
Hull Structure ◽  
Longitudinal Stiffeners ◽  
Oil Tanker ◽  
Side Shell

The occurrence of cracks in the hull structure of oil tankers is an important concern for the maritime industry because crack propagation will reduce collapse strength of deck-stiffened panels and, consequently, decrease the ultimate hull girder capacity of ship’s structures.  Fatigue is an important design criteria for ships to ensure a sufficiently high safety level. Fatigue life predictions of ship’s structural details have traditionally been carried out using S-N approach and the Palmgren-Miner’s rule. The principal objective of such approach is to estimate the time to failure in order to ensure a satisfactory design lifetime of ship’s structural components. Potential cracks are considered to occur in the side shell, in the connections between longitudinal stiffeners and transverse web frame. The main objectives of the present study are to evaluate the fatigue life of vessel’s amidships using the simplified fatigue method, which is based on DNVGL-CG-0129 “Fatigue Assessment of Ship Structures” in order to determine the main cause of the observed cracks on the single skin oil tanker. Fatigue assessment was based on worldwide trade. Longitudinal stiffeners at transverse frames amidships are considered. The results show that fatigue life is generally above 20 years; however, analysis has revealed that the fatigue life of typical stiffener transitions in the side shell is below 20 years. The fatigue lives of side shell longitudinals are regarded as normal for ships built in the period between 1980 and 1990 with extensive use of high tensile steel in the side shell. Inspection and repair proposals of details with fatigue lives below 20 years are advised accordingly. Findings of fatigue analyses provide remaining life assessment, inspection plan definition, determination of repair and modification solutions, and avoiding integrity issues resulting in production downtime and hot work or dry dock.

Reliability-Based Design of the Primary Structure of Oil Tankers

1997 ◽  
Vol 119 (4) ◽  
pp. 263-269 ◽  
Author(s):  
G. Casella ◽  
M. Dogliani ◽  
C. Guedes Soares
Keyword(s):  
Reliability Index ◽  
Development Process ◽  
Steel Grade ◽  
Large Scatter ◽  
Reliability Level ◽  
Reliability Based Design ◽  
Longitudinal Strength ◽  
Global Strength ◽  
Oil Tankers ◽  
Oil Tanker

The present paper describes a reliability analysis carried out for two oil tanker-ships having comparable dimensions, but different design. The scope of the analysis was to derive indications on the value of the reliability index obtained for existing, typical and well-designed oil tankers, as well as to apply the tentative “rule checking” formulation developed within the CEC funded SHIPREL Project. The checking formula was adopted to redesign the midships section of one of the considered ships, upgrading her in order to meet the target failure probability considered in the rule development process. The resulting structure, in view of an upgrading of the steel grade in the central part of the deck, leads to a convenient reliability level. The results of the analysis clearly showed that a large scatter exists presently in the design safety levels of ships, even when the Classification Societies’ unified requirements are satisfied. A reliability-based approach for the calibration of the rules for the global strength of ships is therefore proposed, in order to assist designers and Classification Societies in the process of producing ships which are more optimized, with respect to ensured safety levels. Based on the work reported in the paper, the feasibility and usefulness of a reliability-based approach in the development of ship longitudinal strength requirements has been demonstrated.

Analysis of Stress Field of Fuel Storage Tank Saddle on LNG-Fuelled Ship

2015 ◽  
Vol 1090 ◽  
pp. 222-227
Author(s):  
Yun Qiu Zhang ◽  
Bo Yang Li ◽  
De Dong Hu
Keyword(s):  
Finite Element ◽  
Storage Tank ◽  
Direct Calculation ◽  
Radial Force ◽  
Structure Design ◽  
Ansys Software ◽  
Hull Structure ◽  
Fuel Storage ◽  
Improvement Measures ◽  
Oil Tanker

This paper introduces fuel storage tank arrangement and the saddle structure of 296600 tons oil tanker (VLCC). According to the relevant standard, using ANSYS software, finite element modeling of the saddle and nearby hull structure is created. The radial force distribution function of the saddle is deduced under various conditions. The accurate stress state for saddle and nearby is found out by the application of finite element direct calculation method. Through the analysis of the results, the improvement measures are given and the reference for the saddle structure design is provided.

Time-dependent residual ultimate longitudinal strength - grounding damage index (R-D) diagram

2014 ◽  
Vol 76 ◽  
pp. 163-171 ◽  
Author(s):  
Do Kyun Kim ◽  
Bong Ju Kim ◽  
Jung Kwan Seo ◽  
Han Byul Kim ◽  
Xiaoming Zhang ◽  
...  
Keyword(s):  
Damage Index ◽  
Time Dependent ◽  
Longitudinal Strength

A New Method for Assessing the Safety of Ships Damaged by Grounding

2012 ◽  
Vol 154 (A1) ◽  
Keyword(s):  
Residual Strength ◽  
Structural Damage ◽  
Damage Index ◽  
Sampling Technique ◽  
Damage Scenario ◽  
Strength Performance ◽  
Damage Scenarios ◽  
Longitudinal Strength ◽  
Oil Tankers ◽  
Double Hull

The primary aim of the present study is to propose an innovative method for assessing the safety of ships which have suffered accidental or in-service damages. Only a small number of probable scenarios for accidental or in-service damage representing all possible damage scenarios are selected using a sampling technique in which the random variables affecting the damage are probabilistically characterized. A damage index for the corresponding damage scenario is defined as a function of damage characteristics such as location and extent of the damage. The residual strength performance of a ship with the corresponding damage scenario can then be calculated by analytical or numerical methods. Once this process has been carried out for each of the damage scenarios selected, a diagram relating the residual strength performance to the damage index (abbreviated as the R-D diagram) can be established. This diagram will be very useful for a first-cut assessment of a ship’s safety immediately after it has suffered structural damage. The diagram can also be used to determine acceptance criteria for a ship’s safety against accidental or in-service damage. An applied example is shown to demonstrate the applicability of the proposed method in terms of developing a diagram between the ultimate longitudinal strength versus grounding damage index for four types of double-hull oil tankers – VLCC, Suezmax, Aframax, and Panamax.

A NEW METHOD FOR ASSESSING THE SAFETY OF SHIPS DAMAGED BY GROUNDING

2021 ◽  
Vol 154 (A1) ◽  
Author(s):  
J.K. Paik ◽  
D.K. Kim ◽  
D.H Park ◽  
H.B. Kim ◽  
M.S. Kim
Keyword(s):  
Residual Strength ◽  
Structural Damage ◽  
Damage Index ◽  
Sampling Technique ◽  
Damage Scenario ◽  
Strength Performance ◽  
Damage Scenarios ◽  
Longitudinal Strength ◽  
Oil Tankers ◽  
Double Hull

The primary aim of the present study is to propose an innovative method for assessing the safety of ships which have suffered accidental or in-service damages. Only a small number of probable scenarios for accidental or in-service damage representing all possible damage scenarios are selected using a sampling technique in which the random variables affecting the damage are probabilistically characterized. A damage index for the corresponding damage scenario is defined as a function of damage characteristics such as location and extent of the damage. The residual strength performance of a ship with the corresponding damage scenario can then be calculated by analytical or numerical methods. Once this process has been carried out for each of the damage scenarios selected, a diagram relating the residual strength performance to the damage index (abbreviated as the R-D diagram) can be established. This diagram will be very useful for a first-cut assessment of a ship’s safety immediately after it has suffered structural damage. The diagram can also be used to determine acceptance criteria for a ship’s safety against accidental or in-service damage. An applied example is shown to demonstrate the applicability of the proposed method in terms of developing a diagram between the ultimate longitudinal strength versus grounding damage index for four types of double-hull oil tankers – VLCC, Suezmax, Aframax, and Panamax.

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