.8 shows the resulting
displacements for the load levels at 0.86. These resultsshow a very small increase of both resultant and permanent
displacement with the number of cycles. This suggests
that it is difficult to estimate a fracture cycle by
examining resultant displacement during tests. The relation
between the resultant displacement and fatigue cycle
for some samples is shown in Fig. 9. The increase of the
resultant displacement was small. Fig. 10 shows the relation
of static fracture strain and fatigue resultant strain.
The fatigue fracture stress and strain were normalized to
the static fracture values. As load level decreased, the
resultant fracture strain decreased. For composite materials
and sandwich structures, it is reported that the resultant
fracture strain is proportional to the load level [11].
However the nanohoneycomb structure showed different
behavior.