Tools for early design stage: presentation of LBR-5 Software (original) (raw)
Related papers
A prototype tool for multidisciplinary design optimization of ships
Ninth Congress of the …, 2000
A multidisciplinary design optimization scheme for ships has been developed for use in an integrated ship design environment. Although the system was designed with the intention of using first principle analysis techniques, the containership design examples presented in this paper make use of surrogate parametric analysis modules developed to examine problem formulation issues prior to the availability of the higher fidelity modules. A method of hull shape control based on a barycentric blend of basis hulls is developed. It requires relatively few design variables. In addition to general-purpose geometry, hydrostatic and resistance modules, containership-specific weight, cargo and economics modules were developed. The measure of merit is taken to be the required freight rate. Optimal ship size is found to depend largely on port loading and unloading capabilities. The required freight rate increases and the speed of the optimal ship decreases as voyage length is decreased or fuel cost is increased.
Towards a Ship Structural Optimisation Methodology at Early Design Stage
Ship structural optimisation with mathematical algorithms can be very helpful to find the best solution (minimum weight, minimum cost, maximum inertia, etc). Typically, finite element analysis (FEA) tools are used in ship structural assessment. But, to build FEM model from CAD one is not easy and needs a big amount of manual work. This paper presents an innovative optimisation workflow by which the following steps are automatically carried out, without any manual intervention. First, from 3D CAD model, the idealised CAD model is created by idealisation module taking into account FEM needs. Then, the idealised CAD model is transferred to a FEM tool. After that, the FEM model is meshed, loaded and solved. The obtained results (i.e. stress and weight) are transferred to optimiser tool. The optimiser evaluates the values of the objective function and the constraints previously defined and modifies the design variables (i.e. plate thickness and stiffener scantling) to create a new structural model, going to the next iteration of the loop. This process continues until the optimal solution is reached.
Target Design Levels for Maritime Structures
Journal of Waterway, Port, Coastal, and Ocean Engineering, 2005
The main objective of a project is to verify the requirements and target levels for values of reliability, functionality, and operationality during the useful life of the structure. Such requirements should be provided by external studies carried out by the promoter. In their absence, the engineer has to specify requirements using his or her own criteria. This paper describes a procedure that defines the target levels for maritime structures in terms of their general and operational intrinsic natures. These natures are used to evaluate the importance of the structure as a function of the economic, social, and environmental impact produced in case of serious damage or a total loss of functionality and stoppage, respectively. This procedure gives recommendations for values of a structure's minimum useful life, joint probability of failure against the principal failure modes, adscribed to ultimate and serviceability limit states, minimum operationality, average number of admissible technical breakdowns, and maximum allowed duration of a stoppage mode.
Vessel evaluation for inspection, maintenance and repair on the Subsea Factory
2014
Technical solutions for subsea field developments have seen a rapid growth in complexity over the last years. Today the oil & gas industry is getting ready for a step change by implementing subsea processing facilities. Implementing the equivalent of a topside processing facility on the seafloor brings several challenges, one being the inspection, maintenance and repair (IMR). The main objective of this thesis is to define the challenges related to IMR on a subsea processing facility and to evaluate which vessels are able perform the required IMR operations such a facility would require. The evaluation will be based on the components of the Åsgard subsea compression station. To evaluate vessels ability to perform the IMR operations the data simulation program ORCAFLEX is used. The most critical part of the operation is the splash zone crossing phase so the analysis is based around this. The results from ORCAFLEX are also combined with the weather criteria found at the location.
Vibration Assessment of Ship Structures
Nowadays, noise and vibration problems tend to become an important part of the design process in the naval industry. Vibrations often affect the passengers comfort, but more dangerously may damage the structure, embarked merchandise and equipments. A simple way to avoid vibrations is to prevent the resonance conditions. The paper presents a study about the vibration of local structures (beam structures and stiffened panels) with application in the marine industry. The model has been implemented in FORTRAN into a numerical module and will be integrated in the near future with the LBR-5 generic stiffened structure optimization code.
LNG carrier- Structural design aspects
2009
The EU FP6-IMPROVE Project proposes to deliver an integrated decision support system for a methodological assessment of ship designs to provide a rational basis for making decisions pertaining to the design, production and operation of three new ship generations (LNG, RoPax, chemical tanker). These ship designs enhance the importance of early stage structural optimization and integrated design procedure, which contribute reducing the life-cycle costs and improving the performance of those ship generations. ABSTRACT: IMPROVE has aimed to use advanced synthesis and analysis techniques at the earliest stage of the design process, considering structure, production, operational performance, and safety criteria on a current basis. The nature of shipbuilding in Europe is to build small series of specialised ships. Thus, the IMPROVE project has addressed ships which, with their complex structures and design criteria, are at the top of the list for customisation. The specific objectives of the project have been to: develop improved generic ship designs based upon multiple criteria mathematical models improve and apply rational models for estimation of the design characteristics (capacity, production costs, maintenance costs, availability, safety, reliability and robustness of ship structure) in the early design phase use and reformulate basic models of multiple criteria ship design, and include them into an integrated decision support system for ship production and operation. The operators buying specialised ships generally plan to operate them for the majority of their lives. This means that the maintenance characteristics of the design are very important and for this reason, IMPROVE has focused on designing for a reduction in operation costs. Designing ship structures in such a way as to reduce the problems, for instance, of structural fatigue can help in this cause. Additionally, designing for minimal operational costs can help in increase the structural reliability and reduction of failures thus increasing safety. The targets have been to increase shipyard competitiveness by 10% to 20% and reduce manufacturing costs by 8%-15%, production lead-times by 10%-15%, and to find benefit of 5%-10% on maintenance costs related to structure (painting, corrosion, and plate replacement induced by fatigue). Front and centre of the IMPROVE project, however, has been the three specific ship types selected for the study. The first of these is a 220 000m 3 : capacity LNG Carrier with free ballast tanks, designed by STX-France S.A. The second ship type is a large Ro-Pax ship, with capacity for 3000 lane metres of freight and 300 cars, plus 1600 passengers, with design by Uljanik Shipyard (Croatia). The third ship is a 40,000dwt chemical tanker, designed by Szczecin Shipyard (SSN, Poland).
The development of a formalised multi-objective optimisation procedure for the internal compartmentation of Ro-Ro Passenger ships is presented. The objectives of the optimisation are the maximization of ship's survivability after damage, expressed by the Attained Subdivision Index and the vessel's efficiency, in terms of transport capacity and building cost. The developed procedure is based on the integration of modeFrontier, a software package for Multi Objective and Collaborative Design Optimisation with NAPA, a well-known naval architecture design software package. It is used herein to generate the internal watertight subdivision based on a set of design variables and to perform the stability assessment after damage based on the probabilistic concept as well as all other necessary naval architectural calculations, including transport capacity and structural weight estimation. Case studies for a Ro-Ro passenger ship were performed to demonstrate the applicability of the above procedure, and characteristic results of these studies are herein presented.
Measurement Improvement and Optimization Using Scanning Technology at SAAB AB, Linköping
2010
This master thesis is a development project that is carried out for process improvement and automation for the measurement equipment at "SAAB AB", Linköping focusing on several sections including sheet metal, welding and pipe bending sections. Those are the core sections of the manufacturing of the latest fighter systems from "SAAB AB" such as Gripen, Neuron (unmanned aircraft) and other development projects. SAAB AB has the following issues: Setup time of different parts in the specified departments is higher for the quality checking. The quality inspection of different parts is manual and takes much time. Use of scanning technology to reduce inspection time and increase reliability. The writers of the research work has done a comprehensive investigation and critical analysis of the current condition of the specified departments of "SAAB AB" and made a research work on how to make the process more efficient by implementing automation especially with the use of scanning technology and reduce the huge development cost.