I'm planning to perform a low-velocity impact analysis on a sandwich composite consisting of top and bottom face sheets (Unidirectional fibre reinforced) with 4 plies each and a core (aluminium). The thicknesses are small relative to the other dimensions. After going through various materials, I'm still confused whether which one among the following combinations of elements I should go for -

1) SC8R (Core and face sheets)

2) SC8R (Core) and C3D8R (Face sheets)

3) SC8R (Face sheets) and C3D8R (Core)

4) C3D8R (Core and face sheets)

SC8R - Continuum Shell Element

C3D8R - Solid Element