Parametric Optimisation in Concept and Pre-contract Ship Design Stage

2018 ◽  
pp. 209-245
Author(s):  
George Zaraphonitis ◽  
Timoleon Plessas ◽  
Andreas Kraus ◽  
Hans Gudenschwager ◽  
Gregor Schellenberger
Keyword(s):  
Ship Design ◽  
Design Stage ◽  
Parametric Optimisation

Standard Outfit Package Units in the LPD 17 Ship Design: A Production Impact Study

1995 ◽  
Vol 11 (04) ◽  
pp. 252-263
Author(s):  
Walter L. Christensen ◽  
Philip C. Koenig
Keyword(s):  
Production Scheduling ◽  
Ship Design ◽  
Design Stage ◽  
Traditional Practices ◽  
Preliminary Design ◽  
Wide Range ◽  
Preliminary Design Stage ◽  
And Performance ◽  
Assessment Problems ◽  
Material Ordering

Standard outfit package units for reverse osmosis plants, fire pumps, steering gear, and sanitary spaces were proposed for the LPD 17 amphibious transport dock ship design. The ship was in the preliminary design stage, and it was necessary to determine how this shift to outfit modularity would affect the ship procurement program. Because the use of package units would not have a significant impact on the overall characteristics and performance of the ship, the focus of the investigation was on material ordering and production scheduling. The analysis took account of zone-area-stage outfitting methods and also more traditional practices. With either approach, it was found that the package units did not present any schedule or procurement problems This particular study was focused on a very specific issue, but the approach is applicable to a wide range of production impact assessment problems.

Integrated Multiple Attributive Decision Support System for Producibility Evaluation in Ship Design

2004 ◽  
Vol 20 (03) ◽  
pp. 147-163
Author(s):  
Osman Turan ◽  
Selim Alkaner ◽  
Aykut i. Ölçer
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Ad Hoc ◽  
Labor Cost ◽  
Ship Design ◽  
Design Stage ◽  
Design Development ◽  
Shipbuilding Industry ◽  
Design For X

Ship design today can be viewed as an ad hoc process. It must be considered in the context of integration with other design development activities, such as production, costing, quality control, and so forth. Otherwise, it is possible for the designer to design a ship that is difficult to produce, requires high material or labor cost, or contains some design flaws that the production engineers have to correct or send back for redesigning before production can be done. Any adjustment required after the design stage will result in a penalty of extra time or cost. Deficiencies in the design of a ship will influence the succeeding stages of production. In addition to designing a ship that fulfills producibility requirements, it is also desirable to design a ship that satisfies risk, performance, cost, and customer requirements criteria. More recently, environmental concerns, safety, passenger comfort, and life-cycle issues are becoming essential parts of the current shipbuilding industry. Therefore, "design for X paradigm" should also be considered during the ship design stages. An integrated multiple attributive decision support system for producibility evaluation in ship design (PRODEVIS) is developed to use by industry and researchers in evaluating the producibility of competing ship designs and design features during the early stages of ship design by taking into account cost, performance, risk, and "design for X paradigm" attributes. This developed approach is a fuzzy multiple attributive group decision-making methodology where feasible design alternatives are conducted by a ship production simulation technique. In this approach, an attribute-based aggregation technique for a heterogeneous group of experts is employed and used for dealing with fuzzy opinion aggregation for the subjective attributes of the ship design evaluation problem. The developed methodology is illustrated with a case study.

A Fast Method for the Evaluation of the Dynamic Positioning Capability in Time Domain in the Early Design Stage

2015 ◽  
Author(s):  
Adele Luebcke ◽  
Philip Augener ◽  
Arne Falkenhorst
Keyword(s):  
Time Domain ◽  
Wind Waves ◽  
Ship Design ◽  
Propulsion System ◽  
Design Stage ◽  
Maximum Deviation ◽  
Dynamic Positioning ◽  
Fast Method ◽  
Fast Calculation ◽  
Early Design Stage

Vessels equipped with a Dynamic Positioning (DP) system for station keeping have become quite common on the offshore market. The propulsion system of such ships has the capability to compensate the counteracting environmental forces caused by wind, waves and current. Since the DP capability is an important part of the specification, it is necessary to consider this aspect in the early ship design stage. For this purpose a procedure of a fast calculation method is developed by the authors to predict the limiting environmental conditions and the maximum deviation of the position and the course angle for a pre-established propulsion system.

scholarly journals Optimisation of a Spindle Body Considering the Vibration Prediction of the Entire Milling Centre Construction

Mechanika ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 62-69
Author(s):  
Mateusz WĄSIK ◽  
Krzysztof LEHRICH ◽  
Krzysztof LIS
Keyword(s):  
Machine Tools ◽  
Dynamic Properties ◽  
The Body ◽  
Design Stage ◽  
Machining Parameters ◽  
Factors Affecting ◽  
Parametric Optimisation ◽  
Vibration Prediction ◽  
Ansys System ◽  
Spindle Body

Static and dynamic properties of machine tools have a decisive influence on their accuracy. In case of HSM machine tools, the phenomena associated with them are additionally strengthened by high machining parameters. In order to predict a machine tool behaviour at the design stage, it is necessary to use numerical methods to simulate for its simulation. Thanks to the use of this type of software, it is possible to perform the next step, i.e. the optimisation of the structure. In case of machine tools, due to the multiplicity of factors affecting its accuracy, this should be a multicriterial optimisation. This article presents the results of a vertical milling centre spindle body optimisation using the Finite Element Method. The results of static stiffness and vibration frequency analysis for three bodies (i.e. the body of the form and dimensions proposed by the constructor, the body after parametric optimisation and the body after the form and parametric optimisation including use of different materials) were compared. The optimisation tools available in the ANSYS system were used for the simulation. The calculations were preceded by experimental research and modifications of dynamic parameters performed on their basis using the author's methodology to determine the behaviour of a partially existing structure for different masses of the body being optimised.  

New Approach for Ship Drawing Planning Based on Their Reliability

2020 ◽  
Vol 36 (04) ◽  
pp. 280-290
Author(s):  
Rajko Rubesa ◽  
Tin Matulja ◽  
Marko Hadjina ◽  
Niksa Fafandjel
Keyword(s):  
Lead Time ◽  
Ship Design ◽  
The Other ◽  
Computer Application ◽  
Design Stage ◽  
Design Phase ◽  
Labor Costs ◽  
New Approach ◽  
Total Cost ◽  
Technology Level

Integration of ship design and ship production is necessary for an efficient shipbuilding process, although it requires very complex documentation planning in particular regarding its level of information and the completion scheduling. Optimally organized documentation planning could largely influence the shipbuilding total cost and lead time. Drawings finished with higher level of unreliability are shortening design phase but could result with major repair and rework activities that could increase production time and cost. On the other hand, insisting on fully completed drawings will increase design-stage time and will minimize repair and rework activities, but not necessarily the shipbuilding cost and lead time. This study researches drawing designing sequence and its unreliability due to designing with unknown, incomplete, or unreliable information. Therefore, analysis of documentation planning is performed based on their interdependence, production requirements, production technology level, and labor costs. Finally, a new approach for ship's drawings planning based on the drawing's reliability is proposed with support of developed computer application. Such approach calculates unreliability of interdependent drawings and proposes optimal documentation package regarding its level of information and lunching sequence toward production process.

Determination of Hydrodynamic Masses and Roll Periods of Ships in Shallow Water

2021 ◽  
Author(s):  
Larissa Jannsen ◽  
Stefan Krüger
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Hydrodynamic Forces ◽  
Ship Design ◽  
Design Stage ◽  
Ship Motions ◽  
Design Environment ◽  
Early Design ◽  
Early Design Stage ◽  
Water Effects

Abstract Due to the fast increase of the vessels’ size over the past few years the actual water depth is becoming more and more relevant for seakeeping problems. The highly frequented sea route TSS Terschelling – German Bight for example is a shallow water route for large vessels which are now affected by the reduced keel clearance. Many shallow water depth areas occur also in coastal areas or inland seas. If a vessel is travelling in shallow water sea states, the hydrodynamic forces will change compared to deep water sea states and they are essential for further seaway calculations. Furthermore, a rough but easy evaluation of the incoming seaway is the roll period. Shallow water effects should be taken into account for calculating roll periods and thereby predicting a manageable or risky seaway situation. This paper presents the implementation of shallow water effects into an existing 2D panel code. With this panel code the hydrodynamic forces for the vessel’s frames are calculated based on the potential theory in the frequency domain, which is a validated approach in the early design stage. The panel code is part of the ship design environment E4 which is being developed by the Institute of Ship Design and Ship Safety, among others. With the expanded method it is possible to calculate hydrodynamic forces also in shallow water in all degrees of freedom. Therefore, the frame motions are converted to global ship motions. Furthermore, for the usage in the early design stage the calculations should be fast but also accurate. The obtained calculation results are therefore validated with full scale measurement using Inertial-Measurement-Units.

Sign in / Sign up

Export Citation Format

Share Document