Pre-processing And Post-processing Technologies For Numerical Simulation Of Mold Filling And Solidification Of Castings

In the numerical simulation system of mold filling and solidification processes of castings, the pre-processing module provides the necessary mesh information for all the following modules. It is the prerequisite and foundation of numerical analysis, and its quality of performances directly affects the practicability of the whole system and the accuracy of calculation. The post-processing module (the visualization of the calculation results) displays-al 1 the si mul at ion results concerned by users. It offers the correct basis for the users to carry on projecting policy. Therefore, the pre-processing and post-processing modules take important positions in the whole simulation system.Based on the original SRIFCAST software developed by our institute, and drawing on the experiences of the functions of relevant mature commercial software in foreign countries and consulting a lot of related references, a novel advanced pre-processing and post-processing software based on STL f i les is developed on the platform of the Visual C++ 6. 0 by using a brand-new algori thm and the OpenGL technology. Through calculating contour lines layer by layer for solids, and referring to the scanning line filling technique of computational graphics, more rapid and accurate finite difference mesh generation of 3d multi-materials solids can be done in this paper. In addi tion, the si Ihouette or sol id display of STL sol ids and mesh sol ids can bo realized by using the OperiGL technology. And through simp i Tying the operations of the software interface, users can move, rotate, magnify andminify the 3-D solids and cut the solids at X, Y, Z directions directly by pressing or pulling mouse. When displaying the mesh solids after mesh generating, the treatment measure for the "sewing and mending phenomenon" is firstly proposed, which can be used to improve the display effects of the figures. An automative selection for inflow boundry cells during mold filling processes by mouse is also proposed and developed, which not only makes the input operation more convenient, but also makes the modeling process of the solids more simpler. The 3-dimensional "color- temperature diagram" and "vector diagram" displaying techniques are developed to staticly display the temperature fields of different moments during the mold filling and solidification processes and velocity fields of different moments during the mold filling processes. The computer animations technique is developed to make users to observe the predictive 3-dimensional dynamic processes of the mold filling and solidification processes from any direction on the computer screen.The new pre-processing and post-processing software has been applied to several complex castings in practical production such as the bottom ring segment casting, the impeller casting and the benchmark test casting et. al, and the running results are compared with that produced by using a mature commercial software of foreign country. The results verified the reliability, effectiveness and practicability of the software.