Coupling of thermal and mechanical phenomena by boundary conditions in numerical modelling of solidifying castings

The paper deals with an approach to modelling of some thermo-mechanical phenomena in solidifying castings. Mathematical and numerical models of heat conduction and solid phase growth, as well as models of stress formation due to thermal loading and due to interactions between a casting and a mould are shown. The finite element method (FEM) is applied for building numerical models. The need for taking into account the thermal resistance of air gaps arising between the casting and the mould in thermal and mechanical computations is exposed. A simple solution of this problem consisting in coupling by boundary conditions of thermal and mechanical problems is proposed. Results of computer simulations carried out for 2D examples are presented.