Vibration of thin shells of revolution based on a mixed finite element formulation

A modified Hellinger-Reissner functional for thin shells of revolution is presented. A mixed finite element formulation is developed from this functional which is free from line integrals and relaxed continuity terms. This formulation is applied to the problem of free vibration of spherical and conical shells. Bilinear trial functions are used for all field variables. The quadrilateral curved elements here presented satisfy the C 0 continuity requirement of the functional. In all the results obtained the accuracy is quite good even for a reasonable