The computation results show that the average values of
stresses in the membrane are the same as those of the homogenized
model. However since the boundary conditions
are not really fitting the fine meshing of the detailed model,
the results near the boundary of the domain cannot be used.
This is of course a well-known effect of the Saint-Venant's
Principle acting that “… the difference between the effects of
different statically equivalent loads becomes negligible at
sufficiently large distances from load”.
The method summarised on Fig. 13 gives very good results for
the calculation of stresses due to the assembly process. But as
soon as the fuel cell is in operation, other physical phenomena
must be considered, especially heat exchanges and the
swelling of the membrane due to hydration.