The basic idea of computer solidification simulation is that firstly, the geometric modeling of casting entity is meshed and discretized to obtain the topological data of each element; Secondly, after the continuum is discretized, the differential equations can be easily transformed into algebraic equations and solved in a special model environment; Finally, the calculation results obtained on the node are analyzed and displayed, so as to visualize the calculation results.
The numerical simulation system of casting filling and solidification mainly includes three modules: pre-processing, intermediate calculation and post-processing, as shown in the figure. Among them, the main function of the pre-processing module is to realize geometric condition loading, and mesh generation; The task of the intermediate calculation module is to set the model parameters according to the physical field involved in the casting process, so as to provide calculation simulation for numerical calculation, and predict the casting quality according to the relationship (criterion) between the casting quality or defect and the physical field; The task of the post-processing module is to display the filling and solidification process and the defects predicted by the simulation calculation to the user in an intuitive and clear way, so that the user can directly observe the results of the simulation calculation.
With the progress of science and technology and the rapid development of computer technology, computers have made a qualitative leap in operating system and processing three-dimensional complex graphics, which undoubtedly promotes the rapid development of numerical simulation software. At present, developed industrial countries have their own commercial simulation software, such as ProCAST in the United States, AnyCasting in South Korea, magma in Germany, CastCAE in Finland, Forcast in Spain, casttem in Japan, simulor in France, novasolid in Sweden, etc. many software can simulate the temperature field, flow field and stress field of sand casting, metal mold casting and precision casting, and predict the shrinkage porosity, shrinkage cavity Hot crack and other defects and the structure of each part.
At present, the development direction of foreign casting simulation software, just like the development direction of numerical simulation technology, is developing in the direction of breadth and depth. On the one hand, it is developing to special casting such as low-pressure casting, pressure casting and investment casting, on the other hand, it is moving from macro simulation to micro simulation. ProCAST of the United States and magma of Germany have increased the prediction function of the number of graphite balls and pearlite content in the microstructure of nodular cast iron.
Domestic software started relatively late. At present, the developed commercial software mainly includes ft star of Tsinghua University, Huazhu CAE of Huazhong University of science and technology, strifcast of Shenyang Foundry Research Institute, CASTsoft of Zhongbei University, etc. some functions of these software are equivalent to foreign software, but there is still a big gap in the overall use effect and performance of software, although they can meet the general needs of domestic foundry factories, But we must also clearly see our gap. There is still a long way to go in the future.