FINITE TWIST AND EXTENSION OF A CYLINDRICAL ELASTIC MEMBRANE

We consider a circular cylindrical membrane subjected to longitudinal extension and twist. The associated equilibrium deformation is conside red to be axisymmetric and the analysis is based on a direct two-dimen sional formulation. Wrinkling of the membrane is taken into account in an approximate way by introducing a relaxed strain energy function de rived from the neo-Hook:ean strain energy for isotropic elastic solids . Analytical formulae for wrinkled parts of the membrane are used to c orroborate the results of a numerical treatment of the full boundary v alue problem.