sandwich strcuture

Hi,

While modeling laminated composites we use their material properties (stiffness matrix) to compute the ABD matrix. When E_z of the core is much higher than E_x and E_y, how can we model such a plate using 2D FEM?

I am modeling a plate under three point bending with Abaqus. The plate
is a sandwich structure with aluminum plate (thickness: 5mm), adhesive glue (thickness:
0.02mm) and a kind of foam (thickness: 15mm) bonding together. Their Young’s
modulus is at the order of 100GPa, 1MPa and 100MPa. While in incremental
calculation, the job is always be aborted for not achieving convergence. I just
wonder whether the cause of not achieving convergence should be attributed to
the huge difference in Young’s modulus.