The Impact of Two and Three Dimensional Assumptions on Coupled Structural Mechanics and Microstructure Solidification Modelling

It is usual for computational efficiency to simulate growing alloy dendrites during solidification using a two-dimensional model. However, the fidelity of such simulations is to be questioned, since observations show that three-dimensional models lead to significantly more realistic results in comparison to experiments under many situations. Even in thin sample cases, the properties affecting, for example, mechanical behaviour are intrinsically three-dimensional. However, partly due to the lack of published work on the, topic the impact of 2D assumptions on the evolution and structural mechanical behaviour of dendrites has not been properly explored. In this study, solidification using the Cellular Automata (CA) method was coupled to a Finite Volume Structural Mechanics Solver (FVSMS) capable of both 2D and 3D modelling, applied to a selection of representative problems which clearly demonstrate that structural mechanics is another factor in the modelling of dendrites where two-dimensional assumptions can lead to significantly altered behaviour when compared to three-dimensional reality.