COMPARISON BETWEEN DIFFERENT SURVIVABILITY MEASURES ON A GENERIC FRIGATE

2021 ◽  
Vol 157 (A2) ◽  
Author(s):  
H Liwång ◽  
H Jonsson
Keyword(s):  
Design Process ◽  
Ship Design ◽  
Total Effect

Choosing suitable survivability measures is a demanding task that has to start early in the ship design process. Throughout the design process there is a need for compromises that will define and sometimes limit future operations or capabilities. In this study generic survivability measures are compared. The study also examines the sensitivity of the calculated probabilities to changes in the threat description. The result shows that it is important to investigate the total effect of a hit over a set of relevant ship functions defined for example by survivability levels. The calculations for different threat definitions show that the changes in survivability are substantial when the threat definition is changed. Moreover, the effects of different hit assumptions differ between weapon types. This must be treated as an uncertainty which also should be reflected in the output and weighted into the decisions made, based on the survivability analysis.

Comparison Between Different Survivability Measures on a Generic Frigate

2015 ◽  
Vol 157 (A2) ◽  
pp. 125-134
Keyword(s):  
Design Process ◽  
Ship Design ◽  
Total Effect

"Choosing suitable survivability measures is a demanding task that has to start early in the ship design process. Throughout the design process there is a need for compromises that will define and sometimes limit future operations orncapabilities. In this study generic survivability measures are compared. The study also examines the sensitivity of the calculated probabilities to changes in the threat description. The result shows that it is important to investigate the total effect of a hit over a set of relevant ship functions defined for example by survivability levels. The calculations for different threat definitions show that the changes in survivability are substantial when the threat definition is changed. Moreover, the effects of different hit assumptions differ between weapon types. This must be treated as an uncertainty which also should be reflected in the output and weighted into the decisions made, based on the survivability analysis."

Support Vector Regression-Based Multidisciplinary Design Optimization for Ship Design

2012 ◽  
Author(s):  
Dongqin Li ◽  
Yifeng Guan ◽  
Qingfeng Wang ◽  
Zhitong Chen
Keyword(s):  
Design Optimization ◽  
Support Vector Regression ◽  
Design Process ◽  
Multidisciplinary Design Optimization ◽  
Initial Point ◽  
Ship Design ◽  
Collaborative Optimization ◽  
Multidisciplinary Design ◽  
Support Vector ◽  
Independent Design

The design of ship is related to several disciplines such as hydrostatic, resistance, propulsion and economic. The traditional design process of ship only involves independent design optimization within each discipline. With such an approach, there is no guarantee to achieve the optimum design. And at the same time improving the efficiency of ship optimization is also crucial for modem ship design. In this paper, an introduction of both the traditional ship design process and the fundamentals of Multidisciplinary Design Optimization (MDO) theory are presented and a comparison between the two methods is carried out. As one of the most frequently applied MDO methods, Collaborative Optimization (CO) promotes autonomy of disciplines while providing a coordinating mechanism guaranteeing progress toward an optimum and maintaining interdisciplinary compatibility. However there are some difficulties in applying the conventional CO method, such as difficulties in choosing an initial point and tremendous computational requirements. For the purpose of overcoming these problems, Design Of Experiment (DOE) and a new support vector regression algorithm are applied to CO to construct statistical approximation model in this paper. The support vector regression algorithm approximates the optimization model and is updated during the optimization process to improve accuracy. It is shown by examples that the computing efficiency and robustness of this CO method are higher than with the conventional CO method. Then this new Collaborative Optimization (CO) method using approximate technology is discussed in detail and applied in ship design which considers hydrostatic, propulsion, weight and volume, performance and cost. It indicates that CO method combined with approximate technology can effectively solve complex engineering design optimization problem. Finally, some suggestions on the future improvements are proposed.

scholarly journals A Study into the Validity of the Ship Design Spiral in Early Stage Ship Design

2017 ◽  
Vol 33 (02) ◽  
pp. 81-100
Author(s):  
Rachel Pawling ◽  
Victoria Percival ◽  
David Andrews
Keyword(s):  
Design Process ◽  
Early Stage ◽  
Ship Design ◽  
Complex Process ◽  
University College London ◽  
The University ◽  
Convenient Model ◽  
Balanced Solution ◽  
Block Approach ◽  
Design Spiral

For many years, the design spiral has been seen to be a convenient model of an acknowledged complex process. It has virtues particularly in recognizing the ship design interactive and, hopefully, converging nature of the process. However, many find it unsatisfactory. One early criticism focused on its apparent assumption of a relatively smooth process to a balanced solution implied by most ship concept algorithms. The paper draws on a postgraduate design investigation using the University College London Design Building Block approach, which looked specifically at a nascent naval combatant design and the issues of size associated with "passing decks" and margins. Results from the study are seen to suggest that there are distinct regions of cliffs and plateau in plots of capability against design output, namely ship size and cost. These findings are discussed with regard to the insight they provide into the nature of such ship designs and different ways of representing the ship design process. The paper concludes that the ship design spiral is a misleading and unreliable representation of complex ship design at both the strategic and detailed iterative levels.

The Naval Ship Design/Production Interface

1986 ◽  
Vol 2 (03) ◽  
pp. 185-195
Author(s):  
B. F. Tibbitts ◽  
P. A. Gale
Keyword(s):  
Design Process ◽  
Ship Design ◽  
Design Activity ◽  
Naval Ship ◽  
Current Design ◽  
Design Production ◽  
Design And Production

The paper discusses, from a ship designer's perspective, some of the current topics and issues relating to the interface between naval ship design and production. The current environment within which naval ship design activity is taking place is described. Notable current views on Navy ship design and how it might be improved are summarized. Navy design topics pertinent to improving ship producibility, operability, maintainability and survivability are discussed and examples from recent ship designs are. presented. Issues which result from apparent conflicts in current design initiatives and critiques of the Navy ship design process are highlighted and discussed. Finally, some general conclusions are drawn.

Improving the Early Steel Design Process by Integrating Strength Calculation and Rule Checking Capabilities in a Ship Design Tool

2014 ◽  
Author(s):  
Nicolas Rox
Keyword(s):  
Design Process ◽  
Steel Structure ◽  
Ship Design ◽  
Strength Calculation ◽  
Design Parameters ◽  
Structural Constraints ◽  
Early Design ◽  
Design Software ◽  
Steel Weight ◽  
Steel Design

A well-founded determination of steel structure scantlings is essential during the early design process of a ship or an ocean structure. In the first 4 up to 6 weeks of a new building project, the major part of the final building costs has to be fixed. Amongst others a proper steel weight estimation is crucial. The weight depends on the structural dimensions which are determined mostly by experience and rarely by direct calculations. Therefore, a simple direct strength calculation tool has been integrated in a ship design software. The tool uses structural and general ship design information. Besides the structural constraints, posed by the project design, the steel designer has to fulfill also the structural constraints posed by the classification societies. Normally they are checked with software solutions provided by the societies. However these software tools are not well adapted to the early design process as various design parameters change frequently. For this purpose a link has been created between a rule scantling tool on one side and a design software on the other. The link allows an automated exchange of steel scantlings and project information. By this the modeling and design work as well as the structure scantling and steel weight determination is performed in the design software tool, while the rule scantling tool is only used for a quick assessment of class conformity. With the help of the mentioned methods, the structure can be pre-dimensioned directly based on the early design model in accordance with the classification rules. Furthermore the steel dimensions can not only be optimized with regard to local and global loads, but also with regard to design boundary conditions. In consequence the early steel design process is improved by a more accurate steel scantlings determination and results in a better optimized steel structure as well as severely reduced time spent on the steel iterations.

scholarly journals Systems Engineering – The Hard Way

2018 ◽  
Author(s):  
A R Edmondson ◽  
B Twomey
Keyword(s):  
Design Process ◽  
Systems Engineering ◽  
Cyber Security ◽  
Ship Design ◽  
Life Safety ◽  
Functional Requirements ◽  
Design Processes ◽  
Complex Interactions ◽  
Safety Case ◽  
Marine Vessels

Ship designers, builders, owners, insurers and class societies are becoming ever more aware of the complex interactions of the various systems found on all types of marine vessels. Therefore a design process that acknowledges these demands and assesses the risks posed, and manages them becomes ever more important. This paper seeks to explore some of the, sometimes apparently, conflicting requirements that are placed on designs of new marine platforms and looks at methods that enable these elements to be expressed, understood and managed in the context of an integrated ship design. The demands placed on new vessels include a range of requirements that move away from being solely based around the traditional functional requirements; including the ideas of designing for ease of shipbuilders, operators and maintainers; and now acknowledging the need of a through life safety case, cyber security case, and full obsolescence planning. This becomes ever more complex when consideration is given to how these through life elements are practically managed, with a range of methods, none of which are without their own challenges. It is important to note as these demands are discussed that often a ‘solution’ in the truest sense does not exist and the management of risk becomes a balance between the expected risk, the practicable solution, along with the potential compromises to both programmes and cost. While these demands place huge constraints and drive complexity into design processes, the issues can, and regularly have, been further exacerbated when some of these, or other requirements, are introduced into the design or build phases of projects. Introduction of design drivers should not be undertaken lightly or without expected, and accepted, increases in required resources, both financial and calendrical.

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