Fig 3.

FEM results: a) simulation setup of half structure, where planar symmetry was exploited; (b) deformation of a simple cylindrical skin structure with -0.62 kPa of applied vacuum; c) deformation of bellow Type 3 with -0.21 kPa of applied vacuum; (d) pressure versus deformation graphs for all bellow types; (e) deformation versus strain energy graphs for all bellow types. In (b) and (c): the color legends show deformation values in mm; the gray models show the relative meshes used for the simulations.