The Development of Common Structural Rules for Tankers

2005 ◽  
Author(s):  
Gary E. Horn
Keyword(s):  
General Public ◽  
Development Process ◽  
Project Team ◽  
Structural Requirements ◽  
Technical Aspects ◽  
Structural Rules ◽  
Standardization Process ◽  
The Common ◽  
Common Structural Rules ◽  
The Impact

In late 2001 classification societies Lloyd’s Register, the American Bureau of Shipping and Det Norske Veritas (LR, ABS and DNV) announced plans to standardize a wide number of mutually agreed upon initiatives covering survey and engineering. This standardization process was precipitated as a response to calls for more robust requirements as well as a Class response to calls for improvement made by governments, industry and the general public. One of the initiatives was the establishment of a joint tanker project team (JTP) to develop Common Structural Rules for Tankers so that competition on structural requirements (safety) would be eliminated. Once the common rules are finalized and in effect, they will replace the current tanker rules of LR, ABS and DNV. This paper outlines the rule development process, key technical aspects of the common rules, the impact to the design scantlings, and future maintenance of these rules.

Weight and Cost Optimization of Midship Section Using Common Structural Rules

2020 ◽  
Vol 36 (03) ◽  
pp. 171-180
Author(s):  
Mesbah Sayebani ◽  
Abdolhossein Mohammadrahimi ◽  
Hossein Khoshdel Looyeh
Keyword(s):  
Limit State ◽  
Optimization Technique ◽  
Cost Optimization ◽  
Optimal Solution ◽  
Optimization Procedure ◽  
Computational Tool ◽  
Structural Rules ◽  
Ship Construction ◽  
The Common ◽  
Common Structural Rules

Cost and weight optimization in ship construction are usually investigated in the form of a multiobjective optimization problem. So far, many studies have been carried out to achieve various types of existing optimization objectives and different tools have been developed. Most of the studies in the field of structural optimization have focused on comparing the available optimization algorithms. In this study, a rule-based tool is developed based on the Common Structural Rules (CSRs), which despite its simplicity in application, provides high capabilities in producing an optimal solution. In the developed tool, structural analysis of serviceability limit state is performed by using the relationships of CSRs. The computational tool is created by MATLAB software (Mathworks, Natick, Massachusetts), and the optimization technique is a genetic algorithm. The performance of the computational tool is evaluated by analyzing the midship section of a chemical tanker. In the optimization procedure, weight and cost are assumed to have the same importance. From the results of the developed tool, all components of the weight and cost of ship construction decreased in the optimal solution relative to the initial design.

Research on Some Issues related to Fatigue Assessment based on Latest IACS Harmonized CSR Amendments

2015 ◽  
Author(s):  
Wu Jiameng ◽  
Cai Shijian ◽  
Wang Weifei
Keyword(s):  
Structural Design ◽  
Fe Analysis ◽  
Fatigue Assessment ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Key Issues ◽  
Common Structural Rules ◽  
Oil Tankers ◽  
The Impact

The IACS Harmonized Common Structural Rules (CSR-H) for Bulk Carriers and Oil Tankers has been issued on 1st Jan 2014, and will enter into force on 1st July 2015 to supersede the current CSR version (CSR-BC or CSR-OT). The latest amendments to 01 Jan 2014 version of CSR-H give lots of significant modifications on fatigue assessment. The purpose of this study is to introduce the main changes for fatigue requirement in such amendments, and evaluate their rationality based on some detailed FE analysis for some key issues. Meanwhile, the impact on the structural design, especially on the scantlings, will be discussed as well as some proposal. Some typical bulk carriers and oil tankers are investigated.

Расчетные методы оценки ударной вязкости сварных элементов с трещинами

2020 ◽  
Vol 44 (3) ◽  
pp. 22-36
Author(s):  
Keyword(s):  
Stress Intensity ◽  
Impact Strength ◽  
Welded Joints ◽  
Development Process ◽  
Welded Joint ◽  
Operating Temperature ◽  
Crack Development ◽  
Heterogeneous Structure ◽  
Critical Crack Length ◽  
The Impact

Практика показывает, что для сварных конструкций, эксплуатируемых в условиях Крайнего Севера необходимо уделять внимание работоспособности сварных соединений при низких температурах. Металл сварных соединений в процессе воздействия обработки изменяет свои свойства, снижается ударная вязкость, образуется гетерогенная структура с большой степенью разнозернистости. Чтобы оценивать и иметь возможность правильно контролировать термическое воздействие и последствия сварочного процесса, требуется решить задачу аналитического определения ударной вязкости для всех зон сварного соединения. В настоящей статье представлен инженерный метод оценки ударной вязкости, применимый для любой зоны сварного соединения, в которой имеется острый или особый концентратор напряжений – трещина. Разработанный аналитический метод расчета ударной вязкости отражает качественную и количественную картину взаимосвязи структурно-механических характеристик и работы развития трещины в диапазоне температур 77…300 К. Предложенная схематизация зависимости критического коэффициента интенсивности напряжений от температуры позволила найти коэффициенты, характеризующие свойства материала, и выполнить расчеты изменения предела текучести и предела прочности от температуры эксплуатации. Построены графики зависимости работы развития трещины от температуры эксплуатации для сталей 15ГС и 17ГС, сравнение которых с экспериментальными данными показывает удовлетворительное согласование. Найдено, что при напряжениях предела выносливости отношение работы развития трещины к критической длине трещины постоянно, не зависит от температуры и для сталей 15ГС и 17ГС равно около 10. Ключевые слова: ударная вязкость, работа разрушения, коэффициент интенсивности напряжений, трещина, феррито-перлитная сталь, зона термического влияния. For welded structures under operation in the Far North, attention must be paid to the performance of welded joints at low temperatures. The properties of metal of welded joints are changed in the process of treatment, its toughness decreases, and a heterogeneous structure with a large range of different grain sizes is formed. In order to evaluate and be able to correctly control the thermal effect and the consequences of the welding process, it is necessary to solve the problem of analytical determination of impact strength for all zones of the welded joint. The paper presents an engineering method for evaluation of the impact strength applicable to any area of the welded joint in which there is a sharp or super sharp stress concentrator – a crack. The developed analytical method for calculating the impact strength reflects a qualitative and quantitative codependency of structural and mechanical characteristics and the process of crack development in the temperature range of 77–300 K. The proposed schematization of dependence of the critical coefficient of stress intensity on the temperature made it possible to find coefficients characterizing the properties of the material and to perform calculations of changes in yield strength and tensile strength on operating temperature. Graphs of the crack development process dependency on the operating temperature for 15ГС and 17ГС steels were constructed, and their comparison with experimental data displays satisfactory agreement. It was found that at endurance limit stresses, the ratio of the crack development process to the critical crack length is constant, non-dependent on temperature, and is equal to 10 for 15ГС and 17ГС steels. Keywords: impact strength, fracture work, stress intensity factor, crack, ferrite-pearlite steel, heat affected zone, steel tempering.

Scale Development: Measuring Job-Family Incivility

2019 ◽  
pp. 31-48
Author(s):  
W G S Mahalekamge ◽  
Nilakshi W K Galahitiyawe
Keyword(s):  
Scale Development ◽  
Work Environment ◽  
Development Process ◽  
Workplace Incivility ◽  
Dynamic Processes ◽  
Validity And Reliability ◽  
Development Approach ◽  
The Impact ◽  
Compound Effect

The main contribution of this paper is the development of the job-family incivility scale. This paper seeks to explore the complex inter-relationships between workplace incivility and family incivility dimensions of job-family incivility by examining the dynamic processes by which job-family incivility is initiated and sustained using a scale development approach. In doing so, the paper highlights the absence of valid and reliable measures that estimate the compound effect of workplace incivility and family incivility – referred to as job-family incivility. A scale development process introduced by Quazi et al. (2016) is presented and stages in the construction of the scale are discussed including measures of validity and reliability. The findings of the study demonstrate the validity and reliability of the job-family incivility scale developed by the current researchers. The main aims of this research are to emphasize the impact of workplace incivility and family incivility on the employees in the work environment, and to discuss the techniques that can be used to mitigate such detrimental activities.

The impact of applying the Common Customs Tariff on the armenian export of Cut and Polished Gems to Russia

2019 ◽  
pp. 33-41
Author(s):  
V. L. Harutyunyan ◽  
S. V. Dokholyan ◽  
A. R. Makaryan
Keyword(s):  
Manufacturing Sector ◽  
Practical Implication ◽  
Dominant Role ◽  
New Technology ◽  
Manufacturing Companies ◽  
Medium Term ◽  
Diamond Cutting ◽  
Global Trends ◽  
The Common ◽  
The Impact

The presented study discusses the issues of applying the Common Customs Tariff (CCT) rates of the Eurasian Economic Union (EAEU) on rough diamonds and the impact thereof on the exports of stones cut and polished inArmeniaand then exported toRussia.Aim. The study aims to identify the possible strategies Armenian diamond cutting and polishing companies could adopt as a response to the application of the CCT rates on rough diamonds and how it would affect exports to various destinations, namely to Russia.Tasks. The authors analyze the current state of the gems and jewelry sector and substantiate the need to either integrate it into the jewelry manufacturing sector or to apply various strategies to facilitate exports to either Russia or other destinations in the medium term in response to the application of the CCT rates.Methods. This study uses general scientific methods of cognition, including analytical and methodological approaches and elements of forecasting. Possible strategies the Armenian diamond cutting and polishing companies could adopt in the medium term in response to the application of the EAEU CCT rates are determined using the analytical research method, forecasts in the context of the developments in the Armenian gem processing and jewelry market and global trends, statistical data on the imports and exports of cut and polished gems and jewelry for 2014–2018 published by the UN Comtrade Statistics.Results. Statistics on the exports of processed diamonds from 2014 to 2018 highlights the issue associated with the loss of competitiveness suffered by Armenian companies (mainly in comparison with Indian diamond cutters). The major global trends in the diamond cutting and polishing business indicate that it could be virtually impossible for Armenian cutters and polishers to compete with Indian companies in the medium term if they do not comes to investing in new technology to achieve operational efficiency. For these companies, it is important not to lose the Russian market due to an increase in the tariff rate and concentrate on the processing of gems that are larger than 1 carat. Another strategy to avoid an increase in the customs tariff rates would depend on the Armenian government’s ability to negotiate with Russia in respect of direct imports of diamond stones from Russian manufactures. Two other options for Armenian cutters involve focusing on cutting and polishing of rubies, sapphires, emeralds, etc. or integrating into the jewelry sector either by being the primary supplier or by considering this business as a channel to sell processed diamond stones by setting up their own jewelry manufacturing companies.Conclusions. With CCT going into effect in January 2021 and India’s dominant role in the diamond cutting and polishing business, Armenia needs to carefully consider all of the strategies the Armenian companies could adopt, as discussed above. As a member state of the EAEU, Armenia freely exports to Russia, however, further exports to Russia would depend on Armenia’s ability to ensure that cost-effective operations are in place, or to concentrate on the processing of precious gems rather than diamonds, or to switch to the manufacturing of jewelry items as a major export item.Practical Implication. The findings of this study could be of interest to the Ministry of Economy of the Republic of Armenia and Business Armenia that could be used in elaborating the strategy for the development of Armenian gems and jewelry sector of the economy.

The Impact of Applying the Common Customs Tariff on Armenian Exports of Tobacco Products

2020 ◽  
Vol 26 (4) ◽  
pp. 358-365
Author(s):  
V. L. Harutyunyan ◽  
S. V. Dokholyan ◽  
A. R. Makaryan
Keyword(s):  
Tobacco Products ◽  
The Common ◽  
The Impact

Marine Quality Standards: Their Derivation and Application in the United Kingdom

1985 ◽  
Vol 17 (6-7) ◽  
pp. 1187-1198 ◽  
Author(s):  
G. Mance ◽  
A. R. O'Donnell
Keyword(s):  
Coastal Waters ◽  
Sublethal Effects ◽  
Quality Standards ◽  
Toxicity Data ◽  
Marine Life ◽  
Nickel Zinc ◽  
The United Kingdom ◽  
The Common ◽  
Lead Nickel ◽  
The Impact

This paper discusses the derivation of environmental quality standards for coastal waters and the difficulties of using such standards for controlling industrial discharges. Attention is focused on the common List II substances, copper, chromium, lead, nickel, zinc and arsenic - and their effects on marine life. The adequacy of existing toxicity data is discussed and it is concluded that long exposure tests are required to provide information on sublethal effects. Such data are currently limited. It is also important that consideration be given to the effects that reducing salinities and increasing temperatures have in increasing the toxicity of these substances. The complexity of interpreting the results of laboratory toxicity data to coastal waters is discussed with reference to a study of the impact of an industrial discharge.

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