Sferyczna membrana balonu jest wypełniona gazem o ciśnieniu atmosferycznym i określonej objętości (wartości te są wykorzystywane tylko do definiowania modelu ES). Determine the overpressure inside the balloon due to the given isotropic membrane prestress. The add-on module RF-FORM-FINDING is used for this purpose. Elastic deformations are neglected both in RF-FORM-FINDING and in the analytical solution; self-weight is also neglected in this example.