Two-level finite-element method for thin plates subject to concentrated loads

Abstract

A thin plate subject to concentrated loads (forces or moments) is customarily analyzed either by fine finite-element mesh or by singular elements. This paper recommends an alternative method using conventional finite elements with fine mesh and reducing the number of unknowns by interpolating the nodal displacements by means of the shape functions associated with the previously mentioned singular elements. New element matrices need not be generated and integration is avoided completely. Accurate results under the point load are achieved by a substantially reduced number of unknowns. Both concentrated forces and moments are considered. Accurate superelements can be formed to study plate systems. The procedure presented in this article results in substantially reduced computational effort, and is therefore specially suited for use on microcomputers.