References of "Caprace, Jean-David"
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See detailOptimization of Shipyard Space Allocation and Scheduling using Heuristic Algorithm
Caprace, Jean-David ULg; Petcu, Cristian ULg; Velarde, Marco et al

in Journal of Marine Science & Technology (2013), 18(3), 404-417

In this paper we describe the development of a tool that allows planners to efficiently and effectively plan space within valuable areas of a shipyard. Traditionally, space is considered as resource ... [more ▼]

In this paper we describe the development of a tool that allows planners to efficiently and effectively plan space within valuable areas of a shipyard. Traditionally, space is considered as resource; however, it is difficult to accurately account for and plan its consumption with the current planning software tools available. The spatial scheduling tool described in this paper can be used by planners to manually or automatically reserve space within the shipyard for construction of large blocks over the entire ship erection period. The software is coupled with a heuristic optimization solver which is inspired by an algorithm used for "3D bin-packing problems". The result is the ability to efficiently generate and compare multiple space allocation alternatives in a reduced time with the ultimate goal of maintaining the critical ship erection schedule. Better solution than manual or semi-automatic allocation of blocks can be obtained through the optimization module. [less ▲]

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See detailSpecialist committee V.3 entitled "Materials and Fabrication Technology" of the 18th International Ship and Offshore Structure Congress
Caprace, Jean-David ULg; Schipperen, I.; Andric, J. et al

in Fricke, Wolfgang; Bronsart, Robert (Eds.) ISSC'12 -- International Ship and Offshore Structure Congress (2012)

After years of growth the global economic crisis has deeply affected the shipping industry. There are however clear signs of recovery in the last year. The shipbuilding industry has realised that, due to ... [more ▼]

After years of growth the global economic crisis has deeply affected the shipping industry. There are however clear signs of recovery in the last year. The shipbuilding industry has realised that, due to the crisis, new innovative designs and design and production methods are necessary to decrease operational costs, production costs and emissions, whilst meeting the changing rules and regulations. In this report ISSC committee V.3 discusses recent development in materials and fabrication technology. Chapter 2 focusses on worldwide trends in materials and fabrication methods. Developments in fabrication technologies, such as welding and corrosion protection are dealt with in Chapter 3. Applications of composite materials are increasing. Some main areas of applications and research in those areas are described in Chapter 4. A comparison of current worldwide standards is made in Chapter 5. Chapter 6 gives an overview of current developments in the linking of design and production in computer applications, thus increasing the efficiency of ship building. [less ▲]

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See detailShip Structure Optimization Using CAD/FEM Integration
Amrane, Amirouche ULg; Caprace, Jean-David ULg; Rigo, Philippe ULg

in 11th INTERNATIONAL MARINE DESIGN CONFERENCE (2012, June 11)

In ship structural design, scantling optimization using mathematical algorithms is not yet largely implemented in industry. Optimization with mathematical algorithms can be very helpful to find the best ... [more ▼]

In ship structural design, scantling optimization using mathematical algorithms is not yet largely implemented in industry. Optimization with mathematical algorithms can be very helpful to find the best solution (minimum weight, minimum cost, maximum inertia,…). Typically, finite element analysis (FEA) tools are used in ship structural assessment. But, to build a FEM model from a CAD one is not easy. It needs a big amount of manual work. In the present work, an innovative optimization workflow was developed. The following steps are carried automatically without any manual intervention. First, from the 3D CAD model, an idealized CAD model is created by the idealization module to take into account the FEM needs. Then, the idealized CAD model is transferred to the FEM tool. After that, the FEM model is meshed and loaded. After FEM solving, the results (stress, displacement, volume etc.) are transferred to the optimizer. The optimizer evaluates the values of the objective function and the constraints previously defined and modify the design variables (plate thickness and the stiffener scantling) to create a new structural model. After several iterations, the optimum solution is evaluated. [less ▲]

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See detailTowards a Short Time "Feature-Based Costing" for Ship Design
Caprace, Jean-David ULg; Rigo, Philippe ULg

in Journal of Marine Science & Technology (2012), 17(2), 216-230

Cost is perhaps the most influential factor in the outcome of a product or service within many of todays industries. Cost assessment during the early stage of ship design is crucial. It influences the go ... [more ▼]

Cost is perhaps the most influential factor in the outcome of a product or service within many of todays industries. Cost assessment during the early stage of ship design is crucial. It influences the go, no-go decision concerning a new development. Cost assessment occurs at various stages of ship design development. Economic evaluation as early as possible, in the design phase, is therefore vital to find the best pricefunction compromise for the ship projects. The authors have developed a Feature-Based Costing (FBC) model for cost effectiveness measurements intended to be used by ship designers for the real time control of cost process. The outcome is that corrective actions can be taken by management in a rather short time to actually improve or overcome predicted unfavourable performance. [less ▲]

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See detailToward a Risk Based Simulation for the Erection of an Offshore Windmill Park
Caprace, Jean-David ULg; Petcu, Cristian ULg; Velarde, Marco et al

in Proceeding of the 11th International Conference on Computer Applications and Information Technology in the Maritime Industries (2012, April)

Nowadays, EU shipyards that are facing difficulties due to the global crisis are often trying to diversify their activities. Some of them have already turned to the production of offshore windmill ... [more ▼]

Nowadays, EU shipyards that are facing difficulties due to the global crisis are often trying to diversify their activities. Some of them have already turned to the production of offshore windmill components. The installation and operation of offshore windmills are much more complex than onshore due to the distance and the depth of the water column. This creates problems specific to the production, installation and maintenance of offshore wind turbines. A tool for sequencing and installation simulation has been developed to assess the risks associated to the assembly of wind turbines parks via simulations of the different phases of construction considering various random phenomena such as weather conditions and uncertainties on production time. [less ▲]

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See detailIMPROVE SHIP DESIGN COMPLEXITY (EASYSHIP)
Hage, André ULg; Rigo, Philippe ULg; Caprace, Jean-David ULg

Report (2012)

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the ... [more ▼]

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the productibility of ships, the scientific community and shipyards has developed the concept of Design For Production (DFP) which can be defined as "Design to reduce production costs to a minimum, compatible with the requirements of the vessel to fulfil its operational functions with acceptable safety, reliability and efficiency". DFP optimises all the manufacturing functions (fabrication, assembly, test, procurement, delivery, service, repair, etc.) that reduce the production work content while still meeting the specified design requirements and quality. The goal is to include the impact of design decisions on the production process. Time pressures on commercial ship contracts result in the overlapping of phases of design development, procurement and production. This makes the impact of engineering changes more difficult to manage. There is a need to systematically study the detail design process and its impact on construction with the objective to improve the process and its integration with construction. DFP can significantly reduce the costs, since ships can be quickly assembled from fewer parts. Thus, ships are easier to build and assemble, in less time, with better quality. Designers will save time and money by the reduction of the production complexity. [less ▲]

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See detailA real-time assessment of the ship design complexity
Caprace, Jean-David ULg; Rigo, Philippe ULg

in Computer-Aided Design (2012), 44

The paper introduces an innovative complexity metric for passenger ships taking into account the shape complexity of steel parts, the assembly complexity and the material complexity. The goal is to ... [more ▼]

The paper introduces an innovative complexity metric for passenger ships taking into account the shape complexity of steel parts, the assembly complexity and the material complexity. The goal is to provide the designer with such information throughout the design process so that an efficient design is obtained at the first design run. Real-time assessment of complexity and quality measurements is rather imperative to ensure efficient and effective optimality search, and to allow real-time adjustment of requirements during the design. Application and validation on a real passenger ship show that the new method is effective in giving a complementary aid to decision process for ship designers. [less ▲]

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See detailStructural Optimization: LBR-5 Software and its application
Motta, Dario; Boote, Dario; Caprace, Jean-David ULg

Poster (2011, October)

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for ... [more ▼]

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for merchant ships, passenger ships and motor yachts. Only in the final part of the project some shipyards begin to apply optimization processes, more or less sophisticated, in order to refine the structural design in view of reducing the weight and/or the construction cost. The weight in particular has a very important impact on pleasure vessels, both motor and sailing. Structural modifications suggested by such optimization procedures imply a number of second order changes in related items such as plant, outfitting and others. As a consequence the structural optimization could be particularly useful if it can be applied during the first stages of the project, this way avoiding very expensive time losses and changes caused by any structural modifications. The LBR-5 software has been successfully used to optimize hull structures of a 60 meters mega yacht. Differently from large ships, the mega yacht has not a “cylindrical body” in the central part of the hull. So, a new module of the software has been used in order to analyze several sections of the ship and to perform an overall optimization. For this application the optimization analysis has been carried out by different approaches: assuming the weight as the objective function a gain of about 8% has been achieved, while a least cost optimization allowed a reduction of 15%. [less ▲]

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See detailOptimization of Hull Structures for a 60 meters Mega Yacht
Motta, Dario; Caprace, Jean-David ULg; Rigo, Philippe ULg et al

in Proceeding of the 11th International Conference on Fast Sea Transportation (2011, September)

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for ... [more ▼]

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for merchant ships, passenger ships and motor yachts. Only in the final part of the project some shipyards begin to apply optimization processes, more or less sophisticated, in order to refine the structural design in view of reducing the weight and/or the construction cost. The weight in particular has a very important impact on pleasure vessels, both motor and sailing. Structural modifications suggested by such optimization procedures imply a number of second order changes in related items such as plant, outfitting and others. As a consequence the structural optimization could be particularly useful if it can be applied during the first stages of the project, this way avoiding very expensive time losses and changes caused by any structural modifications. In this paper the structural optimization of a 60 meters megayacht is presented, performed by LBR-5 code developed by the University of Liege. This code is an optimization tool specifically designed for structures composed by stiffened plates and stiffened cylindrical shells. The optimal solution is reached through an optimization algorithm based on convex linearization and a dual approach. The LBR-5 software has been successfully utilized to optimize hull structures of a 60 meters megayacht. Differently from large ships, the mega yacht has not a “cylindrical body” in the central part of the hull. So, a new module of the software has been used in order to analyze several sections of the ship and to perform an overall optimization. For this application the optimization analysis has been carried out by different approaches: assuming the weight as the objective function a gain of about 8% has been achieved, while a least cost optimization allowed a reduction of 15%. [less ▲]

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See detailDiscrete Event Production Simulation in Shipyard Workshops
Caprace, Jean-David ULg; Moreira Freire, Roberto; Assiss, Luiz Felipe et al

in Proceeding of the 21th COPINAVAL (2011, September)

Nowadays, shipyards are making huge effort to efficiently manage equipments and resources such as laborers, gantry cranes, transporters, steel and block stock yards, etc. Previously scheduling was ... [more ▼]

Nowadays, shipyards are making huge effort to efficiently manage equipments and resources such as laborers, gantry cranes, transporters, steel and block stock yards, etc. Previously scheduling was manually performed by an experienced manager of a shipyard. But such a scenario leads to undesirably long times for producing scheduling results. In addition, the quality of the scheduling results was usually not optimal. To improve the overall process, Discrete Event Simulations (DES) have been developed and recently use in shipbuilding industry. The use of simulation-based design and virtual reality technologies leads to higher efficiency in terms of work strategy planning, and offers, as a result, significant productivity gains. It gives computer-supported answers to the major questions: when and where to produce what and with which resources depending on the availability and restrictions of resources and materials. The first part of the paper presents a multi-criteria analysis to select the most appropriate DES software for shipyards. Then, the second part of the paper shows production simulation model focusing on block erection stage. Two different blocks splitting are compared and then the results are discussed. [less ▲]

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See detailHow to improve the ship efficiency
Caprace, Jean-David ULg

Conference (2011, August)

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See detailOptimisation of ship structures
Rigo, Philippe ULg; Caprace, Jean-David ULg

in Guedes Soares, Carlos; Garbatov, Y.; Fonseca, N. (Eds.) et al Marine Technology and Engineering (2011, May)

Limiting CO2 emissions is a great challenge being faced by society today. Society, through the United Nations Framework Convention on Climate Change (UNFCCC), and actors like the EU, is applying pressure ... [more ▼]

Limiting CO2 emissions is a great challenge being faced by society today. Society, through the United Nations Framework Convention on Climate Change (UNFCCC), and actors like the EU, is applying pressure on all industries, including the shipping industry, to reduce CO2 emissions. This paper presents a way to decrease the GHG emissions by ship scantling optimisation, i.e. decreasing steel weight and keeping the production cost at an acceptable level. The authors first review the links between “Design” and “Optimization” and secondly define the place of “Ship Structure Optimization” within the general framework of a “Ship Optimization”. Then, the LBR-5 ship structure optimisation software is presented. It is based on a convex lin-earization coupled with a dual approach and is based on a rational assessment of the ship structures behaviour. Few applications of structures optimization are then presented. [less ▲]

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See detailDiscrete Event Production Simulation and Optimisation of Ship Block Erection Process
Caprace, Jean-David ULg; Trevisani Da Silva, Clarice; Rigo, Philippe ULg et al

in Proceeding of the 10th International Conference on Computer Applications and Information Technology in the Maritime Industries (2011, May)

Nowadays, shipyards are making every effort to efficiently manage equipments and resources such as labourers, gantry cranes, transporters, steel and block stock yards, etc. The block erection scheduling ... [more ▼]

Nowadays, shipyards are making every effort to efficiently manage equipments and resources such as labourers, gantry cranes, transporters, steel and block stock yards, etc. The block erection scheduling of a gantry crane has thus far been manually performed by a manager of a shipyard. Such a scenario leads to undesirably long times for producing scheduling results. In addition, the quality of the scheduling results may not be optimal. To improve the overall process, block erection discrete event simulations have been developed in this study by using techniques of optimization. The first results presented in this paper are promising even if some future work must be realized. [less ▲]

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See detailShip Complexity Assessment at Concept Design Stage
Caprace, Jean-David ULg; Rigo, Philippe ULg

in Journal of Marine Science & Technology (2011), 16

A innovative complexity metric has been introduced in this paper and provides a solution to compare similar or different ship types and size together at the contract design stage. The goal is to provide ... [more ▼]

A innovative complexity metric has been introduced in this paper and provides a solution to compare similar or different ship types and size together at the contract design stage. The goal is to provide the designer with such information throughout the design process so that an efficient design is obtained at the first design run. Application and validation on a real passenger ships have shown that a significant correlation between the error of an engineer’s judgement of omplexity and the cost assessment error can be obtained. It follows that this tool could be used to improve the knowledge of ship’s complexity at the contract design stage or even to try to optimise their design if the complexity criteria are not fixed by the shipowners. [less ▲]

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See detailEarly Structural Assessment and Optimisation of Passenger Ships
Caprace, Jean-David ULg; Bair, Frédéric ULg; Rigo, Philippe ULg

in Procceding of the International Conference on Design and Operation of Passenger Ships (2011, February 23)

A multi-criteria optimisation of a passenger ship is conducted in this paper. Minimum production cost and minimum steel weight are the both objective studied. Moreover the study answers to the following ... [more ▼]

A multi-criteria optimisation of a passenger ship is conducted in this paper. Minimum production cost and minimum steel weight are the both objective studied. Moreover the study answers to the following question: "From when will the higher costs of high tensile steel should be offset by a gain of steel weight?". For a passenger ship, a significant reduction of the steel weight, for a controlled raise of the gravity centre, should lead either to a reduction of fuel consumption either to an additional deck, which for a ship owner means a faster return on investment. Pareto frontiers are obtained and results are validated by classification rules. [less ▲]

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See detailData Mining in Ship Construction and operation
Caprace, Jean-David ULg

Conference (2011, January)

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See detailMulti-criteria Scantling Optimisation of Cruise Ships
Caprace, Jean-David ULg; Bair, Frédéric ULg; Rigo, Philippe ULg

in Ship Technology Research = Schiffstechnik (2010), 20

A numerical tool for the optimisation of the scantlings of a ship is extended by considering production cost, weight and moment of iner tia in the objective function. A multi-criteria optimisation of a ... [more ▼]

A numerical tool for the optimisation of the scantlings of a ship is extended by considering production cost, weight and moment of iner tia in the objective function. A multi-criteria optimisation of a passenger ship is conducted to illustrate the analysis process. Pareto frontiers are obtained and results are verified with Bureau Veritas rules. [less ▲]

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See detailLinking design and production in computer applications for increased efficiency
Caprace, Jean-David ULg

Conference (2010, September)

Shipbuilding has been severely affected by the global economic crisis. Demand for new ships has collapsed world wide since summer 2008 causing an unprecedented levels of overcapacity in the global cargo ... [more ▼]

Shipbuilding has been severely affected by the global economic crisis. Demand for new ships has collapsed world wide since summer 2008 causing an unprecedented levels of overcapacity in the global cargo ship fleets. The current crisis gives impulses for a radical think to adopt new designs to reduce the life cycle costs and to decrease the environmental impact. Leading shipping companies recognise that low life cycle cost and low emission save costs, open quality sensitive markets and will be the key driver to profitability in the future. The speaker will present some possible techniques to improve the link between design and production in order to boost the competitiveness of worldwide shipyards. Modularizations, ease of manufacturing, standardization, virtual reality, production simulation, product life cycle management, are some of these techniques illustrated in the presentation. The speaker will also draw the trends for the future years. [less ▲]

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See detailA complexity metric for practical ship design
Caprace, Jean-David ULg; Rigo, Philippe ULg

in Proceeding of PRADS 2010 (2010, September)

The paper introduces an innovative complexity metric for practical ship design taking into account the shape complexity of steel parts, the assembly complexity of steel components and the material ... [more ▼]

The paper introduces an innovative complexity metric for practical ship design taking into account the shape complexity of steel parts, the assembly complexity of steel components and the material complexity of the structure. The goal is to provide the designer with such information throughout the design process so that an efficient design is obtained at the first design run. Real-time assessment of complexity and quality measure-ments is rather imperative to ensure efficient and effec-tive optimality search, and to allow real-time adjustment of requirements during the design. Application and validation on a real passenger ship show that the new method is effective in giving a complementary aid to decision process for ship designers. [less ▲]

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See detailScantling Multi-objective Optimisation of a LNG Carrier
Caprace, Jean-David ULg; Bair, Frédéric ULg; Rigo, Philippe ULg

in Marine Structures (2010), 23(3), 288-302

Numerous real-world problems relating to ship design are characterized by many alternatives. Moreover in the scantling design, minimum production cost, minimum weight and maximum moment of inertia ... [more ▼]

Numerous real-world problems relating to ship design are characterized by many alternatives. Moreover in the scantling design, minimum production cost, minimum weight and maximum moment of inertia (stiffness) are conflicting objectives. Ship design is a complex endeavour requiring the successful coordination of many different disciplines, both technical and non-technical. Basic design is the least defined stage of the ship design process and seeks to define the optimal amidships section structure. For that purpose, recent improvements were made to the LBR-5 software to optimise the scantling of ship sections by considering production cost, weight and moment of inertia in the optimisation objective function. A real multi-criterion optimisation of a LNG carrier is conducted in this paper to illustrate the analysis process. Pareto frontiers are obtained and results highlight that LBR-5 is competitive software to optimise scantling of ships at very early design stage with management of critical problems studied normally at a later step of the design. [less ▲]

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