(shearing and bending)
the lateral stiffnesses of the fiber and mattress cover are negligible.
Since the mattress cover is easy to wrinkle,
the in-plane stiffness of the cover may also be ignored.
This assumption makes it possible to perform only one FEA
for a given body pressure distribution
during the whole optimization process
since a change in placement of the fiber optic cable will not change the deformed shape of the mattress surface.
This makes using a global searching GA possible.