kravich: переводы

→This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government
(MEST) through GCRC-SOP (Grant No. 2011-0030671).

→Additionally the authors assured that the STEP could be a baseline for the development of new shipbuilding CAD sys- tem because of their qualified data structure and well proven methodologies.

→For the verification of the SPPM, a prototype system has been designed and implemented using ACIS geometry mod- eling kernel and ObjectStore - an object oriented database management system - in Window XP environment. As a client application, the stability and the LSTR assessment for a damaged condition was selected, and the changes of stability and LSTR conditions was simulated according to the change of the load cases.

→In this paper, a STEP based ship product model (SPPM) was introduced and proposed as a framework for the integra- tion of CAE applications and related design information in ship initial design stage. For the design of SPPM, an object- oriented hybrid methodology based on IDEF family of meth- ods was defined and introduced as an information modeling tool for the development of shipbuilding information system.

→For several years, the 3-D product model has been a standard in shipbuilding. However, 3-D design is still mainly used in the detail design phase. In some rare cases, the use of 3-D design extends to earlier design phases for hull form design and some naval architectural calculations.

→Fig. 13 is an result of STEP AP216 physical file generated from the hull form model.

→Fig. 12 is the result of the stability and LSTR assessment, which shows simultaneously display GZ curve, LSTR curves and related information in accordance with the change of load case based on SPPM.

→Fig. 11 shows an result of grid generation for CFD analysis from SPPM.

→For stability and LSTR assessment, the load cases must be defined based on the product model. The load case is a certain condition of ship, normally and intensionally defined for de- sign purpose. The basic data required for the load cases are directly acquired from the product model. By changing con- ditions, we can simulate the changes of ship stability such as trim, rolling angle, GZ-curve and damage stability and so on. Simultaneously LSTR condition is checked through weight distribution, buoyancy distribution, shearing force distribution, longitudinal bending moment distribution and so on.

→For the verification of the effectiveness and the applicabil- ity of SPPM, grid generation for CFD analysis, stability and Longitudinal STRength (LSTR) assessment were performed. Also generation of STEP data file for the exchange of design data to other system was tested.

→After completion of the hull form model, the compartment and cargo modeling continues for the SPPM. The compart- ment is a functional unit of space such as tanks, engine room, cabin, and so on. The compartment consists of one or more rooms. The room is a geometrical unit defined by the bound- ary surfaces. A special coordinate system, the frame system based on the frame number and space of the ship, is used for compartment definition. After the definition of an object geometrically, the properties of that object are also defined and checked automatically or interactively through GUI windows designed for each object. Also the cargo information is de- fined for each compartment and stored in SPPM.

→The implementation of SPPM starts with the hull form modeling, and followed by the compartment modeling and cargo definition processes. For the hull form modeling, the basic curves (center line contour, bottom and side tangent lines, frame lines, water lines, etc.) are defined by using offset data. These curves are faired automatically or interactively, and used as the input data for the surface modeling in Non- Uniform Rational B-Spline (NURBS). The deck surface is also defined by the shear and camber information.

→2) Verification of Product Model

→1) Implementation of Product Model

→2. Implementation and Verification of SPPM

→In this modeling system the SPPM framework provides the interfaces to ACIS kernel and ObjectStore database.

→Fig. 8 shows the architecture of the modeling system for SPPM. As shown in the figure, ACIS geometric modeling kernel was used for the geometric definition and representa- tion. And for the persistent storage and management of the product model data, an object-oriented database management system - ObjectStore - was used. This database solution inte- grates the persistence mechanism between the application objects. The OpenGL graphic library was utilized for the visu- alization of the product model, and Visual C++ programming language for the implementation of Graphical User Interface (GUI).

→To implement a product model based on the SPPM frame- work, a mean of Application Interpretation Model of STEP (AIM) level representation is needed.

→The SPPM framework is a set of application level (ARM, Application Reference Model of STEP) C++ class libraries. This framework provides the STEP based standard structure of product model data and the common functionalities (behav- iors) of the client applications in the initial ship design activi- ties. Also the SPPM framework provides the interfaces to external application programs (written in Fortran and C lan- guage) and resources such as geometry kernel and database management systems.

→A product model is a structured set of objects which are the instances of classes. Modeling system or modeler is a soft- ware system, normally known as CAD system, to build a product model by instancing the classes.