A SIMPLIFIED DISPLACEMENT-ROTATION FORM FOR THE EQUATIONS OF MOTION OF NONLINEARLY ELASTIC SHELLS OF REVOLUTION UNDERGOING COMBINED BENDINGAND TORSION

By appropriately defining two displacements and a rotation, it is show n that the equations of motion of a shell of revolution undergoing com bined axisymmetric bending and torsion, in which the extensional strai ns and the rotations may be arbitrarily large, can be given a form in which there are three effective extensional strains and two effective bending strains, each of which is only linear or quadratic in the disp lacements and rotation.