CAE Technology: A Tool for Mold Design
The mold industry is an important basic industry of the national economy. In automobiles, electronics, instrumentation, aviation, and home appliances, parts that rely on molds account for 60% to 80%. The design and manufacturing standards of molds directly affect the quality of products and Productivity. Mould design technology has also experienced the rapid development of CAD/CAM/CAE. At present, CAE technology has gradually been widely used and developed. There have been a lot of CAE commercial software for guiding mold design, such as Dynaform, Deform, Autoform, Superform, Superforge. , Pam-stamp, Fastform, FastBlank, Hyperform, Fastamp, Moldflow, Polyflow, etc. These softwares are mainly for the virtual tryout of the forming process and play an important guiding role in the field of mold design. HangZhou Changchen Industrial Co.Ltd. , https://www.hzcc16.com
Application in extrusion die and process design 
Figure 1 Equivalent strain at the end of the positive extrusion simulation process. In the virtual prototype of the volumetric forming process, the Deform software is used more often. Deform is a finite element based process simulation system used to analyze metal forming. Various forming processes in its related industries. Through the analogy of the entire processing process on the computer, the engineers and designers are instructed to design the molds, which reduces the cost of expensive on-site test molds, thereby improving the efficiency of mold design, reducing production and material costs, and shortening the research and development cycle of new products. Forging, deep drawing, extruding, rolling, spinning and other plastic forming processes can be performed on a computer to perform virtual test, and die stress, elastic deformation and damage analysis can also be performed. 
Figure 2 Equivalent stress distribution at the end of positive and negative compound extrusion <br><br> In the extrusion process die design process, CAE simulation technology can be used to achieve extrusion process formulation and key die size design. Figure 1 to Figure 3 show the results of simulations for a positive extrusion, a positive and a negative compound extrusion, and a back extrusion process for a product. Through the use of CAE technology to optimize the original process and mold design, and achieved good results. 
Fig. 3 Equivalent strain stress distribution diagram at the end of back extrusion <br> Application in die design
Dynaform is used more often in sheet metal forming virtual simulations. Dynaform is easy to use and contains many automatic functions that can easily solve the most complex forming problems. Dynaform includes complete CAD, pre-processing functions, analysis functions, and post-processing functions. Dynaform supports Windows, LINUX and UNIX operating systems, providing users with a full-featured and affordable solution. The use of CAE technology to simulate the stamping process to guide the mold design can greatly save the cost of trial mold and improve the mold design quality. 
Figure 4 Aircraft Parts Mold Schematic 
Figure 5 The stamping defect of the initial design
In die design, CAE simulation technology can also be used to improve and optimize the process and die structure. Figure 4 shows an aircraft part produced using a stamping process. As shown in Fig. 5, through the CAE simulation of the original forming process, it can be found that the local area of ​​the material is not fully stretched, while the other area is severely thinned, resulting in a significant quality problem of the formed part. For these forming defects, by modifying the mold structure, the drawbeads are arranged in place to change the flow of the local material, so that the material flow tends to be uniform and the forming defects are eliminated. Fig. 6 and Fig. 7 are the analysis results after modifying the mold structure, basically reaching a more ideal state. 
Figure 6 The final designed product thinning rate 
Figure 7 forming limit diagram
Application in injection mold design
In the injection molding CAE technology, Moldflow's MPI (Moldflow Plastics Insight) is currently used more often. The software can simulate the entire injection molding process, optimize the part design, mold design and injection molding process, and simulate plastic flow simulation and thermoplastic filling and holding pressure processes. At the same time, it is possible to optimize the optimal gate position, optimize molding parameters, and balance flow channels, and even simulate gas-assisted injection molding processes for pressure control and volume control.
In the injection mold design, the CAE simulation technology can also be used to improve and optimize the process and mold structure. Figures 8 through 10 show the application of CAE technology in guiding plastic products and mold design. Figure 8 shows the initial design of the product. The CAE simulation technique calculates the amount of deformation in the Z direction of the product to be 18.8mm. By adjusting the process and mold structure, the amount of deformation can be reduced by 3mm, and it is always difficult to significantly reduce the amount of deformation. Finally, by changing the design of the product, the amount of deformation was significantly reduced. After the product was changed, the maximum deformation in the Z direction was 7.1 mm. This result is basically acceptable to users. Figure 9 shows the modified product structure with ribs on the back of the product. Figures 10 and 11 show the deformation before and after the product change. 
Figure 8 The initial design of the product 
Figure 9 Design after product change
Application status and prospect
CAE technology is an indispensable technology in future mold technology. CAE analysis technology is an important development direction for the future mold design and development, and it will be widely used. However, CAE technology currently has some problems and problems that cannot be avoided in the mold design process. 
Figure 10 Deformation map of initial product
On the one hand, the application of CAE technology has not been fully realized and there is a certain degree of resistance in the promotion of CAE technology in the enterprise. Most of the current enterprise mold design completely depends on experience. On the other hand, CAE technical engineering and technical personnel are relatively lacking. The application of CAE technology to engineering and technical personnel has high requirements. It will not be enough to use the software alone. It must also have solid theoretical knowledge and rich practical experience. At the same time, few people have these capabilities. 
Figure 11 Deformation after product change
The continuous development of CAE simulation technology and its close integration with mold design technology will have an important impact on the mold design method. Through the simulation of the mold under various working conditions, various information about the mold will be obtained, which will enable the designer to understand the mold and the forming process more deeply, which will help to improve the design efficiency, reduce the research and development risk, and promote the mold design technology. progress.