船体结构初步设计英文文献和中文翻译(3)
Fig. 3: An Example of Part Representation by the Proposed Data Structure Semantic Product Modeling Function Various modeling function such as generating functions of a panel and a stiffener, which is used during hull structural modeling, is a tool to generate and modify the data structure by using user input data and the data generated from internal calculation such as intersection calculation. A suitable modeling function for each structural part is needed, because a modeling method is different in different structural part. Thus, in the developed system, many modeling functions for various structural parts were implemented based on detailed modeling methods for them by design experts, and the functions construct contents of the data structure by using the non-manifold geometric modeling kernel. Fig. 4 shows an example of the modeling function for generating a new panel (“Panel 2”) on existing panel (“Panel 1”). Panel 1EFace 1Panel 1 Panel 1BB 1 BB 1 ModelModelEBody 1 EBody 1Plate 1 Plate 1EFace 1 EFace 1EFace 1 EFace 1Panel 1 Panel 1BB 1 BB 1 ModelModelLayer LayerFrontLayer FrontLayerSeam 1 Seam 1EBody 1 EBody 1Plate 1 Plate 1EFace 1 EFace 1EFace 1 EFace 1Panel 2 Panel 2BB 2 BB 2 ModelModelLayer LayerMiddleLayer MiddleLayerSeam 1 Seam 1EBody 2 EBody 2Plate 2 Plate 2EFace 2 EFace 2EFace 2 EFace 2¨Seam 1 Seam 1EEdges EEdges Layer1 Layer1FrontLayer FrontLayerPanel 1 Panel 1Layer2 Layer2MiddleLayer MiddleLayerPanel 2 Panel 2EEdge 2 EEdge 2Panel 1Panel 2EFace 1EFace 2Seam 1(EEdge 2)¨void AddPanel(geometry, attributes) {MakeDataStructure(attributes); //
Step cMakeNonmanifoldModel(geometry); // Step dMakeRelation(); // Step e}void AddPanel(geometry, attributes) {MakeDataStructure(attributes); // Step cMakeNonmanifoldModel(geometry); // Step dMakeRelation(); // Step e}c Generation ofdata structureModeling function for generating a panelA function to store hull structural informationin the data structured Generation oftopological entitye Construction ofpart relationship Fig. 4: An Example of the Modeling Function for Generating a Panel As shown in Fig. 4, the modeling function is comprised of three steps. In the first step, a container of the data structure for the new panel is generated. In the second step, non-manifold topological entities representing the shape of the new panel are generated. In the last step, relationship information between the existing and new panels is constructed by using the seam. Generating Function of Production Material Information The generating function of production material information means a function to generate various information for production planning, such as weight, center of gravity, joint length for welding, painting area, etc. of building blocks, from the 3D CAD model for a hull structure. Seam 1PanelStiffenerHoleSeam 2 StiffenerSeam 1PanelSeam 2Block Butt Seam¨Rectangular solidRectangular solid containingthe building block ¨Intersectionbetweenthe rectangular solidandall structural partsWeight, center of gravity, and painting area ofeach structural part¨ weight, center of gravity, painting area, etc.of the building blockSeam (butt or fillet)¨ joint length between building blocks,joint length in the building block Fig. 5: Generating Function of Production Material Information by Using the Rectangular Solid As stated above, the hull structural information in the data structure is the information of a panel unit, and this constructs structure systems such as bulkheads, an inner bottom, girders, and so on, which correspond to design objects in the initial design stage. However, since the production material information should be provided as a unit of a building block, the intersection calculation between the hull structural information and a rectangular solid (Fig. 5) or a subpision plane (Fig. 6) is needed in order to generate such information. Here, the rectangular solid represents an object containing a building block, and the plane represents an object containing a block butt seam to generate building blocks. ¨Intersectionbetweenthe subpision planeandall structural partsSeam 1PanelStiffenerHoleSeam 2 Seam 2PanelSeam 1Block Butt SeamSeam 2 StiffenerPanel¨Subpision planeWeight, center of gravity, and painting area ofeach structural part¨ weight, center of gravity, painting area, etc.of the building blockSeam (butt or fillet)¨ joint length between building blocks,joint length in the building blockSubpision plane containingthe block butt seam Fig. 6: Generating Function of Production Material Information by Using the Subpision Plane User Interface The user interface (UI) is a tool to get input data, which are needed for performing the modeling function, from a designer. There are two types of the UIs; one is a dialog-based UI, the other is a script file-based UI. In the developed system, the script file-based UI is introduced, which supports more general modeling function and is more expandable than the dialog-based GUI, although it is hard to implement the script file-based UI. User interfaceSketch section¨Section from intersectionbetween hull form andcompartment model1 Generate a sketch.¨Part modeling(Side Web)2 Generate a part. ¨3 Input attributes.Modeling functionData structureUser interfaceMakeSideWebPanel(geometry, attributes)Construct datastructure for side webProvide geometryand attributesModeling by using a script fileA tool to get input data froma designer for performingthe modeling functionsCompartment modelfor a 320K VLCC Fig. 7: Hull Structural Modeling Procedure by Using the User Interface As shown in Fig. 7, the hull structural modeling procedure of the developed system is comprised of three steps. In the first step, a designer generates a sketch section that a structural part will be modeled by using the intersection calculation between a compartment model for a ship and infinite plane. In the second step, he generates the structural part as if making a 2D drawing by using various commands and functions for a script file. In the last step, he inputs design attributes of the structural part.