Application of computer aided engineering CAE in t

Application of Computer Aided Engineering (CAE) in precision casting (middle)

3 discussion on the key problems and related technologies of Ca precision casting process

in recent years, monomer technologies related to Ca precision casting technology, such as 3D CAD design, reverse engineering, rapid prototyping, gating system CAD, numerical simulation of casting process (CPS) and special casting, have made considerable progress. These achievements have laid a foundation for the formation of integrated CA precision casting technology, It promotes the rapid development and application of Ca precision casting technology. In order to make each monomer technology successfully used in CA precision casting, we must eliminate the interface between each other and organically combine these technologies. Thus, in product development, we can achieve real advanced design + Advanced Materials + advanced manufacturing. 3.1 three dimensional model generation and electronic document exchange

how to get an accurate electronic data model of parts is the first step of discussing the practical significance of this topic. With the development of 3D CAD software, reverse engineering and other technologies, this work has become simple and fast. This paper mainly introduces the process of entity modeling and data conversion using ideas. Ideas9 integrates 3D modeling and reverse engineering modeling modules. Through the mastermodeler module, complex models can be obtained (see Figure 2), which can not only carry out parametric design with full geometric constraints, but also carry out free and innovative design with arbitrary geometric and engineering constraints; Surface design provides the modeling function of many kinds of free-form surfaces, including variable sweep, boundary surface and so on. Reverse engineering freeform can process the point cloud information collected by the digitizer, create curves and surfaces, and design them. After the surface is generated, it can directly generate RPM files, or it can be transferred back to the main modeling module for processing (see Figure 4). After the entity file is generated, it needs to be converted into STL file (see Figure 3) as the input of RP equipment. During the conversion process, attention should be paid to selecting the name of the forming equipment, usually sla500, and the output accuracy of the triangle is between 0.005~0.01. When using magicrp treatment, it should be noted that multiply by 25.4 to get the actual design size

3.2 numerical simulation of solidification process

3.2.1 numerical simulation principle of solidification process | mechnet | welcome to visit Chinese mechanical expert

casting is a process in which liquid metal fills the mold cavity, solidifies and cools, which contains many complex phenomena that affect the quality of castings. In actual production, experience is often used to evaluate whether a process is feasible. For a casting, the process finalization needs many tests and repeated exploration. Finally, according to the casting results of various test schemes, the casting process scheme that can meet the design requirements is selected. Many times of trial casting will cost a lot of human, material and financial resources

although the casting process is very complex and there are many accidental factors, it still follows the basic scientific theories, such as fluid mechanics, heat transfer, metal solidification, solid mechanics, etc. In this way, the casting process can be abstracted into solving the problems of liquid metal flow, solidification and temperature change, that is, to solve the Fourier heat conduction equation and elastic-plastic equation under the given initial and boundary conditions. The development of computer technology makes it possible to solve the numerical solution of physical processes. Computer numerical simulation can be used to quantitatively describe the extremely complex casting process

abstract through mathematical and physical methods, the casting process can be characterized as the coupling of several kinds of equations:

1 heat conservation equation: 2 continuity equation: 3 momentum equation: the commonly used numerical simulation methods are mainly finite difference method and finite element method. The mathematical model of finite element difference method is simple, the derivation is simple and easy to understand, and it takes up less memory. However, the calculation accuracy is general. When the casting has complex boundary shape, the error is large, and the difference lattice needs to be converted into the finite element lattice for stress analysis. The finite element method technology calculates the elements according to the variational principle, and then carries out the overall synthesis of the elements. The simulation accuracy is high, and it can solve the problem of castings with complex shapes. No matter what numerical method is used, the numerical simulation software of casting process should include three parts: pretreatment, intermediate calculation and post-processing. Pretreatment mainly provides geometric information of castings and moulds for intermediate calculation; Various physical parameters and casting process information of castings and shells. The intermediate calculation is mainly based on the physical field of the casting process design, which provides a calculation model for numerical calculation and for improving the technical level of automotive non-metallic materials and products in China under such circumstances for a long time, and predicts the casting quality according to the relationship between the casting quality or defects and the physical field. Post processing refers to the intuitive graphical expression of the calculated results. The numerical simulation system of casting process