Mesh	Exact	Present	wpresent /wexact	ABAQUS	wabaqus /wexact
20x20	1.8248E-05	1.74362E-05	0.9555	1.77866E-05	0.9747
30x30		1.79593E-05	0.9842	1.81676E-05	0.9956
40x40		1.81878E-05	0.9967	1.82150E-05	0.9982