Jean-David Caprace

Maintenance/repair and production-oriented life cycle cost/earning model for ship structural optimisation during conceptual design stage

The aim of this paper is to investigate the effect of the change in structural weight due to optimisation experiments on life cycle cost and earning elements using the life cycle cost/earning model, which was developed for structure optimisation. The relation between structural variables and relevant cost/earning elements are explored and discussed in detail. The developed model is restricted to the relevant life cycle cost and earning elements, namely production cost, periodic maintenance cost, fuel oil cost, operational earning and dismantling earning. Therefore it is important to emphasise here that the cost/earning figure calculated through the developed methodology will not be a full life cycle cost/earning value for a subject vessel, but will be the relevant life cycle cost/earning value. As one of the main focuses of this paper is the maintenance/repair issue, the data was collected from a number of ship operators and was solely used for the purpose of regression analysis. An illustrative example for a chemical tanker is provided to show the applicability of the proposed approach.

A real-time assessment of the ship design complexity

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.

A Data Mining Analysis Applied to a Straightening Process Database

Abstract The paper presents the results of a data mining analysis aiming to improve the cost knowledge of the labour intensive straightening process. The data mining approach yields a formula linking the straightening cost to the sections scantlings (plate thickness, dimension and inter-distance of longitudinal stiffeners, dimension and inter-distance of transversal frames) and to other section characteristics.

Optimization of Surface Utilization Using Heuristic Approaches

Abstract A scheduling problem arising in factories producing large building blocks is modelled applying optimization techniques. The application is a shipyard workshop producing prefabricated keel elements. The objective is to maximize the number of building blocks produced in the factory during a certain time window. The solution combines a Guided Local Search heuristic with Fast Local Search techniques. A final discussion explains the additional real-life issues arising in the industrial application and how firm-specific constraints can be conveniently considered by the model.

Multi-criteria Scantling Optimisation of Cruise Ships

Abstract A numerical tool for the optimisation of the scantlings of a ship is extended by considering production cost, weight and moment of inertia 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.

Optimisation of Ship and Offshore Structures and Effective Waterway Infrastructures to Support the Global Economic Growth of a Country/Region

This paper includes the following parts:• Ship Structure Optimization: methodology to perform ship scantling optimization, decreasing steel weight and keeping the production cost at an acceptable level. We 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”.• Ship impacts (Collision), with applications to navigation lock and dry dock gates: these gates have to be designed taking into account accidental loads, such as ship collisions. A new simplified analytical method is proposed, based on the so-called super-element method. This method was developed to rapidly assess the crashworthiness of the collided structure and avoid high computational effort of numerical simulations.• Inland waterway Navigation and the development in South America of Inland Waterway Classifications.• EMSHIP, European ERASMUS MUNDUS education program (www.emship.eu): the unique master’s degree in Ship & Offshore Structures awarded by the prestigious European Erasmus Mundus Program. EMSHIP shares the outstanding experiences of educators, trainers, industrial partners and students in the rapidly developing areas of marine and offshore engineering industry.

Estimation of Welding Distortions and Straightening Workload Through a Data Mining Analysis

This paper will present a way to minimize cost in the shipbuilding industry by using the results of a data mining analysis aiming to improve the cost knowledge of the straightening process. This statistical analysis was based on production data from a shipyard and has the scope to establish an assessment formula of the straightening workload. An intermediate step of the analysis was to estimate the welding distortions appearing in stiffened panels. Those generated formulas are useful to improve the research in the following domains: production simulation, cost assessment of ship hull, structure optimization, design for production, etc.

Ultimate Strength of Stiffened Panels Assessment Taking Into Account Model Uncertainty

This paper presents a methodology to take into account model uncertainties related to the load-end shortening curve of stiffened panels. This method is a part of a research activity carried out at University of Liege. His goal is to propose a reliability based model to assess hull girder ultimate strength using a progressive collapse algorithm. The numerical results presented here concern the load-shortening model chosen for this research, which is based on Bureau Veritas rules. Model uncertainty is quantified as a parameter considered as a random variable. Four statistical moments (mean, standard deviation, skewness and kurtosis) of this parameter are calculated and analyzed using a data-base of stiffened panels test results published in recent years. In order to increase the number of “actual” values for the statistical assessment, the data-base is completed with non-linear finite element analysis results. The paper contains also some recommendation for the implementation of the proposed method in ultimate strength reliability based analysis.Copyright