Second, CAD modeling and finite element analysis of a spacecraft component 2.1 Pro/E software introduction Pro/E software discards the wireframe and surface models in traditional CAD software and directly considers 3D entities. By allowing the design environment to fully evolve from 2D or 2D and 3D blending to pure 3D mode, designers can better capture their design intent and inspire design in this most intuitive 3D design environment. Previous page next page
The 3D entity of Pro/E is based on feature modeling techniques. In Pro/E, the objects that are targeted include geometric features, non-geometric features, part models, assembly models, mold models, machining models, etc., through which the designer has intrinsic properties, existence patterns, and presence states. Accurately grasp to get the ideal model.
All objects in Pro/E are built into a single database. And this database is unique and complete, thus ensuring that any design made in Pro/E is also fully relevant. Parameter changes can occur anywhere in the design process and can be reflected in the relevant aspects of the entire design process. Designers can rely on this function to completely abandon the traditional working methods, and achieve the process of part design, mold design, assembly design, and machining design.
Pro/E's 3D feature entities are fully parameterized, adaptive and intelligent. The entity is driven by complete and accurate parameters and data. Each design dimension of the product model corresponds to a parameter. The designer can establish the relationship between the parameters by command or relational form to obtain the model of the required design. .
2.2 CAD modeling of a spacecraft part In the process of solid modeling, it is necessary to design according to the dimensions on the 2D drawing. Some complex curves should be treated flexibly in pro/E. Maybe different people should design the same part. The time spent will vary greatly, which is caused by the different methods used to draw the graphics. For example, a method with a variable cross-section scanning with a variable cross-section will save time. For example, a simple cube can be scanned or stretched. There are some angled rockers around a thin plate. Is it in the standard mode or in the sheet metal mode.
2.3 Introduction to Marc Software This discussion is based on the 2D drawings of several parts of a spacecraft in the Pro/E software environment for 3D modeling. After modeling, the MSC/Marc finite element analysis software is used to simulate the forming process of the parts. To understand the strain process and state of the part before processing, as well as the force and heat of the part, and provide important performance parameters of some parts.
Msc.Marc/Mentat is the most advanced non-linear finite element software in the world. It is a product of MSC.Software Coorperation (MSC). MSC.Mentat is a pre- and post-processing graphical interactive interface for a new generation of nonlinear finite element analysis. The former closely integrates MSC.Marc and MSC.Mentat into a high-level general finite element software for solving complex engineering problems and completing academic research.
2.3.1 MSC.Mentat
MSC.Mentat is a pre- and post-processing interactive interface for a new generation of nonlinear finite element analysis, seamlessly connected to the MSC.Marc solver. It has the first-class solid modeling function with ACIS as the core; fully automatic two-dimensional triangle and quadrilateral, three-dimensional tetrahedral and hexahedral mesh automatic segmentation modeling ability; intuitive and flexible definition of multiple material models and definition of boundary conditions; analysis process Control definition and submission analysis, automatic inspection of the integrity of the model; real-time monitoring and analysis capabilities; convenient visualization of processing results; advanced lighting, rendering, animation and film production and other graphical functions and direct access to commonly used CAD / CAE Systems such as: ACIS, AutoCAD, C-MOLD, IGES, MSC.Nastran, MSC.Patran IDEAS, VDAFS, STL, etc.
2.3.2 MSC.Marc
MSC.Marc is a full-featured solver for advanced nonlinear finite element software, which embodies the perfect combination of theoretical methods and software for finite element analysis for more than 30 years. He has a strong structural analysis and inability. Can handle a variety of linear and nonlinear structural analysis. It provides a rich library of units, connected units and special units. MSC, Marc's Institutional Analytical Materials Library provides solutions for simulating linear and nonlinear problems such as metals, non-metals, polymers, geotechnical, and composite materials. In order to further improve the calculation accuracy and analysis efficiency, MSC.Marc software provides a variety of powerful loading step adaptive control technology to automatically determine the analysis loading step size. MSC.Marc's excellent mesh adaptive technology automatically adjusts the mesh density with multiple error criteria, which ensures the calculation accuracy and greatly improves the computational efficiency of nonlinear analysis. In addition, MSC.Marc supports fully automated mesh redrawing to correct mesh distortion caused by excessive deformation and to ensure continued large deformation analysis.