We now consider an infinite space which contains an array of
penny-shaped cracks, each having the same radius
*a*_{0} subjected to the same asymptotic condition as in the previous
example. The centroids of these cracks are located regularly with an
interval of 4*a*_{0} in each coordinate direction, but the orientation
of each crack is taken random. Fig.4.6 shows the mesh
for 512 cracks (total DOF=241,664), with each crack having 472
DOF. Fig.4.7 shows the crack opening displacements; we
superimposed the non-dimensional crack opening displacement
()
plotted in the normal direction on the non-dimensional
mesh
.
The required CPU times with the original FM-BIEM and the
new FM-BIEM are 4930(sec) and 3633(sec), respectively, while the
numerical results obtained with these methods coincided. This result
shows that the new FM-BIEM is more efficient than the original FM-BIEM
when the boundary elements are distributed densely in the domain.