Warpage simulation and the experimental verification of an L‐plate sand mold casting by using the thermo‐elastoplastic FEM code

The warpage of casting parts is a critical issue, especially for large industrial products. Besides, it is difficult to predict the warpage accurately in the casting process because of its complex dependence on mechanical and thermal factors such as the constitutive law of the high temperature metal, the temperature history of the entire part and the restrictions imposed on the deformation by the mold wall. In the present paper, a 3D finite element software V-Shrink developed within the VCAD System Research Program is used to simulate the warpage of an L-plate sand mold casting. It takes into account the thermal coupling between the cast and the mold with non-uniform heat transfer coefficient depending on the local air-gap thickness. 1) The thermo-elastoplastic constitutive law with the temperature dependency of the yield stress is used for the thermal contraction analysis. 2) The simulated warpage of the L-plate casting is in good agreement with the experimental data obtained by a 3D digitizer. Furthermore, the well-known technical finding that the inelastic strain caused by the temperature dependence of the yield stress and the local delay of the temperature drop is a dominant factor of the warpage, is confirmed by the simulation.