This article starts from the design requirements, introduces the application of PRO/E software in the field of large-scale steel structures, describes the top-down parametric technology of PRO/E software, lists the three-dimensional design flow of large-scale steel structures, and according to large-scale steel Structural product characteristics, summed up skeleton framework as the core of the framework design, solid modeling rules and plans out the main technical solutions, and finally focused analysis of the system integration on the three-dimensional design work patterns and nesting design and management of the positive impact.
I. Introduction
The large-scale steel structure is an important part of civilian products at Wuchang Shipyard. It mainly includes large bridge products and complete sets of equipment. At present, Wuchang Shipbuilding Factory has rapidly emerged from the domestic large-scale steel structure manufacturing industry, and it is critical to constantly strive for market development. It is necessary to strive for absolute competitive advantages and enhance independent innovation capabilities. In view of this, PTC's PRO/E 3D design software was introduced to continuously promote the innovation of design patterns and management concepts in the traditional large-scale steel structure manufacturing field.
At the end of 2005, Wuchang Shipyard used PRO/E software to carry out three-dimensional design of large-scale steel products such as the Pearl River Huangpu Beibei Cable-stayed Bridge, Hangzhou Bay Nanhang Bridge, Pengshuicheng Cabin, and Hangzhou Jiangdong Bridge, and steadily achieved two-dimensional The transition to 3D design work mode and the integration of data management software, nesting software and other system software on the basis of preliminary results achieved in PRO/E 3D design, and the establishment of an enterprise manufacturing information management platform, thus enhancing the entire process of product design Organization, management and control.
Second, the main features of three-dimensional design of large-scale steel structures
The combined application of the PRO/E 3D design software with the traditional large-scale steel structure production design results in a large leap in the 3D design of large-scale steel structures compared with the conventional 2D design, which is embodied in the following three aspects:
(1) Development of design ideas . The three-dimensional design based on PRO/E software adopts the top-down design idea, that is, the overall framework model of the product is first structured, and then the detailed design of the unit parts and parts is performed in turn. Because the multi-level distribution skeleton in the framework model contains the main positioning and reference information of the entire product, this design idea enhances the product master's overall ability to grasp the product.
(2) Improvement of technical content . Under the PRO/E parametric design technology, all features such as points, lines, surfaces, and solids are controlled by variable size parameters and constraints. The basic map information of the construction drawing is automatically generated by the 3D model, and it is headed by the skeleton. Changes in dimensions and constraints will quickly drive the correlation between relevant 3D models and 2D drawings. Therefore, the tightness, accuracy, and change-response capabilities of the design compared to the relatively loose graphical information combinations under 2D CAD techniques. Obviously enhanced.
(3) Enhanced visualization and process control . The 3D design transforms the designer's professional 3D space imaging into an intuitive 3D digital model, which brings the design closer to the actual product. The 3D modeling itself is a digital simulation of the product manufacturing and assembly process, enabling potential processes in the product building process. And technical problems were discovered and resolved in advance in the design process.
Three, top-down parametric three-dimensional design process for large-scale steel structures
Under the top-down parametric design guideline of PRO/E software, the three-dimensional design of large-scale steel structures can be roughly divided into three major beats: design preparation, model construction, and chart generation shown in Fig. 1.
Fig.1 Main flow of three-dimensional parametric design of large-scale steel structure
3.1 Preparation of 3D Design for Large Steel Structures
In the process of three-dimensional design of large-scale steel structures using PRO/E software as a technology platform, the design preparation section can be sequentially performed according to the three sub-links of design planning, program design, and frame design.
3.1.1 Three-dimensional design of large-scale steel structures
After the official receipt of the product design task, in order to ensure the correct and orderly follow-up design, it is necessary to carry out the following four main content design planning:
(1) At the time of plan review , first, the potential omissions and uncertainties in the blueprint of the design institute shall be clearly and promptly eliminated, and then focus shall be placed on the positioning benchmarks and plate thickness distribution rules of the transverse and longitudinal sections of the steel structure, and then sign approval plans for approval. The design blueprint has three-dimensional design conditions.
(2) Process separation , that is, the product supervisor should combine the production conditions in the factory to further clarify the types of steel segments/segments and split and optimize the plate units horizontally and vertically in each segment/segment.
(3) Develop a plan for drawing plans . The plan should include a list of detailed drawings, relevant persons responsible, and a delivery period.
(4) General-purpose parts planning , which mainly classifies and statistics the common parts and components between each sub-section and each section.
3.1.2 Scheme Design of Three-dimensional Frame Model of Steel Structure Products
Under the PRO/E software platform, since the three-dimensional frame model of a steel structure product is essentially a model tree assembled from a top-down assembly file and a skeleton file through a certain level and a series of virtual assembly relationships, the corresponding framework The design plan should mainly include three parts: the assembly tree structure design, the skeleton design and the assembly relationship design.
First: product frame model tree structure design.
In the design of the assembly tree structure of large-scale steel products, the main assembly structure is usually product → sub/section → three subassembly levels. The substructure should be laid out under this three-level assembly assembly; at the same time, the specific product technology and Production organization and other characteristics, the main assembly structure can be adjusted.
Second: product frame model skeleton design.
After the design of the assembly tree structure is completed, the inheritance scheme between the assembly-level skeletons should be clearly defined according to the layout and linkage of the skeleton and the top-down approach to ensure that the skeleton has sufficient control over the entire product model, and then the typical skeleton The overall planning of the modeling program is carried out, and the detailed design of each concrete skeleton modeling scheme is performed.
Third: product framework model tree assembly relationship design.
To ensure that the product frame model is compact, the assembly relationship design should be carried out according to the following rules:
(1) Select the assembly type according to the order of the default assembly, coordinate system alignment assembly, positive assembly (referring to the alignment of three pairs of assembly surfaces) and reverse assembly (referring to the matching of two pairs of assembly surfaces and alignment of a pair of assembly surfaces);
(2) Assembling features with priority reference skeleton;
(3) Determine the forward and reverse assembly relationship with the upper assembly, based on the principle that the components (observed from the side of the oblique axis) are visible on the structural side when they are independently displayed.
3.1.3 Three-dimensional frame model design of steel structure products
After the design of the product framework model is completed, the three-dimensional design of the framework model can be performed. Generally, the relatively complete framework design can be divided into the following two main processes in sequence:
(1) The top assembly of the architecture product , which in turn includes the creation of the product assembly, the creation and editing of the product's vertical and horizontal total skeletons, and the creation and assembly of the various sub-section assemblies;
(2) Frame design of each segment/segment , including creating and editing segment/segment skeletons under the segments/segments, creating and assembling each horizontal and vertical element, and creating and editing the corresponding skeleton under each element.
For complex products, under the premise of ensuring effective control of the product, parallel design division can be performed on the design tasks of the sub-frame/segment to shorten the design cycle and help the designer to smoothly enter the design role.
3.2 Three-dimensional solid model structure of large-scale steel products
According to the characteristics of the simple features of the large-scale steel structure products and the complex relationship between the assembly structure, the three-dimensional solid modeling of the sub-sections should follow the following rules:
(1) The default assembly and skeleton reference priority : that is , the default assembly of the newly created components as far as possible in order to reduce the difficulty of assembly; the physical characteristics of the parts design and assembly as much as possible with reference to the skeleton, in order to ensure that the skeleton from top to bottom Effective control.
A three-dimensional model of a bridge
(2) The physical characteristics of parts are generated mainly by stretching, supplemented by digging : that is, for rectangular plates or profiles, the entities are usually stretched according to the cross-sectional features; whereas for profiled plates, the basic profile is usually first along the plate thickness direction. Stretching into solids, and then through a partial digging to get special-shaped entity features.
Under the above modeling rules, three-dimensional solid modeling of segments/sections can be performed according to the following process:
(1) Create and use the default assembly relationship to assemble the first occurrence of a single element;
(2) Complete the assembly and feature modeling of the components under each unit;
(3) Introduce and assemble recurring unit and common parts;
(4) Completion of the creation, assembly and feature modeling of sub-/ segment parts;
(5) Fill in technical information such as material, specifications, and process routes of the three-dimensional models of the sub-sections;
(6) To check the integrity and correctness of the 3D model and improve the model;
3.3 Chart Generation for 3D Design of Large Steel Structures
According to the manufacturing mode of large-scale steel structures from the parts → single parts → points/sections, the designers must provide the blanking, assembly and construction drawings in order.
3.3.1 Improve the Drawing Process of Parts Drawing
Currently, the blanking plan is mainly generated by the independently developed nesting software through the nesting design. The PRO/E software mainly provides the floor plan with process information and logos to the nesting software through the part separation. The part separation mainly includes three processes:
(1) After-treatment of parts: According to the requirements of the welding process of the products, add process information such as margin and compensation amount to the edge of the part, and obtain the blanking outline of the parts;
(2) Generate a plan view of the part;
(3) Improve the parts drawing: Add marking information such as groove and key dimensions on the two-dimensional plan of the part.
3.3.2 Drawing Process and Major Technical Schemes for Producing Construction Drawings
At present, the production and construction drawings are all in the prescribed form, with the following flow chart of the single-part drawings:
(1) Create atlas files and add 3D models of each element as object associations;
(2) Generate a single unit view;
(3) Improve the single-element drawing information, including creating ball markers, drawing auxiliary lines, drawing diagrams, dimensioning, symbols, and inserting notes.
After the unit drawing of the previous page is completed, the subsequent unit drawing can be performed in the order of (2)→(3).
The plotting features of the segment/segment production map mainly lie in that the associated object is a segmented/segmented three-dimensional model and there are special matching intra-table pages, and the three-dimensional model has a one-to-many relationship with the atlas page.
In the process of using PRO/E to output single-unit and segment/segment assembly drawings, the following solutions are proposed for common technical problems:
(1) The definition of complex perspectives and profiles : Through the redirection view tool and the view manager, respectively, in the 3D modeling environment, when the viewing direction is perpendicular to the profile, it can be used in the same view.
(2) The generation of view auxiliary information : Firstly, according to the BOM table ball mark in the drawing environment, the quick and automatic association identification of each component in the view is realized, and secondly, the auxiliary line information of the view is obtained through the line sketch or offset view boundary. Solved the problem of labeling of auxiliary dimensions, and also solved the problem of marking of welds and other symbols by establishing a standard symbol library;
(3) Generation of schematic diagrams: Since the schematic diagram usually contains process information, the cost in the theoretical 3D model is too large to be reflected. Therefore, two solutions are proposed: First, the 3D model correlation generation method, that is, according to the characteristics of the schematic diagram. The corresponding three-dimensional model is established, and then the three-dimensional model is associated with the drawing to generate a corresponding view. Secondly, the drawing method of the element, that is, drawing the schematic graphic element information through a line drawing function in the drawing environment.
IV. Three-dimensional design of large-scale steel structures under system integration environment
In the process of combined application with traditional large-scale steel structure production design, PRO/E as a design software mainly provides a more advanced design platform and produces a better information carrier, and the full realization of the value of 3D design depends on the entire design management system. The architecture. In view of this, we adopted the integration of PRO/E software and data management software first, and then used data management software as the information management hub to implement an overall integration scheme for the three-dimensional design information to effectively control system software such as nesting software. Through system integration, the three-dimensional design of large-scale steel structures has had a positive influence especially on the organization work mode and nesting management.
4.1 Improvement of the 3D Design Organization Work Mode for Large-scale Steel Structures
In the environment with only PRO/E software, the three-dimensional design of large-scale steel products mainly adopts a file sharing working mode. That is, in the shared project project folder, a framework model total assembly, each sub/section, and a common parts sub-folder are created, and then the team members perform corresponding sub-section/three-dimension design on the shared folder.
In the environment of system integration, the team's three-dimensional design mainly adopts a combination of local modeling and regular warehousing. That is, the product's framework model is first put into the database, and then the data design software is used to assign the design tasks to the designers. The designers access the database through the authentication, find the corresponding design task and extract the corresponding frame model to the local computer. , can be three-dimensional modeling in this machine, to be modeled to a certain stage and then send the design data back to the database, to achieve data updates. This system-integrated 3D design work mode helps to improve the overall efficiency of the 3D design of the team and data management control.
4.2 Improvement of Management Mode for Large Steel Structures
Before system integration, PRO/E software mainly provides complete parts drawings for nesting software. The management of nesting design is mainly controlled by experience; after implementing system integration, the three-dimensional design information generated by PRO/E software is used as an information carrier. The role has been fully played in the design of nesting. Through the data processing of the management software, the creation of nesting tasks, the editing of nesting parts lists, and the records of the whereabouts of the nested parts can be performed on the model tree of the product's three-dimensional model, and the selection of parts during the nesting task can also be performed. Strictly follow the material parameters, plate thickness and other process parameters defined in the product's three-dimensional model to achieve accurate management and control of nesting design with three-dimensional design information.
V. Conclusion
Through the combined application of the PRO/E software and the three-dimensional design of large-scale steel structures, the production design of traditional large-scale steel structures has been significantly improved in terms of design ideas, technical content, and organizational work patterns. As applications continue to deepen, the technical potential and integration advantages of PRO/E software will be continuously tapped and revealed. The 3D design process will be further optimized, the technical content of 3D design will be further improved, and the value of 3D design information will be used. With continuous improvement, the lean, intensive and economic benefits of traditional large-scale steel structure design and manufacturing will also be significantly improved. At the same time, design management personnel should focus on continuously enhancing software application capabilities, independent innovation capabilities, organizational management, and coordination work capabilities, so as to give full play to the advantage of team-parallel collaboration in large-scale steel structure three-dimensional design.
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