Table 4.

The selected stiffnesses computed by various numerical model (with different number of four-node bi-linear FEs used) and simple analytical formula.

Model	Number of Elements	${\mathit{A}}_{11}(\mathbf{N}/\mathbf{mm})$	${\mathit{A}}_{22}(\mathbf{N}/\mathbf{mm})$	${\mathit{D}}_{11}\left(\mathbf{Nmm}\right)$	${\mathit{D}}_{22}\left(\mathbf{Nmm}\right)$
FEM 1	8	3608.8	1961.4	13,786	6651.4
FEM 2	32	3565.0	1960.8	13,774	6471.3
FEM 3	112	3553.4	1960.6	13,755	6426.5
FEM-4	448	3549.4	1960.5	13,749	6415.2
FEM-5	1792	3548.0	1960.5	13,746	6412.4
Analytical	-	3360.0	1937.4	13,449	6226.7