Finite-Element Analysis of Shells of Revolution by Two Doubly Curved Quadrilateral Elements

Two finite-element models, one derived from the principle of minimum total potential energy and the other derived from a modification of the same, are considered for linear analysis of shells of revolution. The first is a compatible'displacement model in which an element interior displacement field that generates compatible interclcment boundary displacements and rotations is assumed, but no rigid-body displacement modes are included in the element displacement field; the second is a hybrid displacement model in which rigid-body modes are included explicitly in the displacement field in the interior of the element and a Lagrangian multiplier technique is needed to satisfy the.