Elastic-Plastic Analysis of Thick-Walled Pressure Vessels With Sharp Discontinuities

Application of special isoparametric finite elements is presented for the elastic-plastic analysis of shells of revolution. General isoparametric elements are selected which, in the form of a layered system, are capable of representing a solid of revolution. The customary Kirchhoff-Love hypothesis is not invoked and solutions therefore apply both to thin and thick shells of revolution. Sharp discontinuities in geometry, circumferential ribs and/or grooves, as well as cellular walls may be studied. A special feature is the development of an element permitting sliding at the element interfaces with or without friction. The illustrative examples include a pressure vessel with a circumferential crack in the wall thickness, and a circular plate consisting of two disks which can slide along their interface. The solutions are limited to axially symmetric problems. Flow theory of plasticity is used in the inelastic regions.