Element Creation and Termination Technique for Thermal Stress Analysis in Casting Process

초록

In a conventional simulation of casting process, stress analysis is not carried out until all parts of the cast are completely solidified due to the rheological behavior of metals. However, this approach may not give an exact estimate of the thermal stress due to non-uniform cooling rates. To overcome this difficulty, we have developed a new technique for thermal stress analysis that considers molten materials and solidifying shell in the mushy region. The finite elements of the molten materials are terminated first and deleted in the element list but once the temperature of the cells becomes lower than the liquidus point, i.e., at mushy zone, these elements are created at proper time steps. All of the material properties are temperature-dependent. For our analysis, FDM/FEM hybrid method is used. Heat flow analysis is carried out by the FDM and thermal stress analysis by the FEM. The results of the proposed method are compared with those of the earlier methods, and it is confirmed that the proposed method can simulate real-time phenomena of casting process successfully.