Structural instability and natural vibration analysis of thin arbitrary shells by use of the Semiloof element

✍ Scribed by R. A. F. Martins; D. R. J. Owen

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 828 KB
• Volume: 11
• Category: Article
• ISSN: 0029-5981
• DOI: 10.1002/nme.1620110308

✦ Synopsis

Abstract

At present the Semiloof element is probably one of the most efficient available for the solution of thin shells of arbitrary geometry. Experience in static situations indicates that accurate results can be obtained for non‐trivial geometric and loading configurations with relatively coarse meshes. Variable thickness shells or discontinuous thicknesses can be accommodated and no difficulties are encountered in modelling sharp corners or multiple junctions in structures. The element is basically non‐conforming but some measure of C^1^ continuity is provided by the introduction of normal rotation variables at Loof nodes on the element boundary. This paper examines the element behaviour when applied to elastic instability and vibration situations. An eigenvalue solution scheme based on Sturm sequences is presented which does not require the usual elimination of a percentage of the total nodal variables by static condensation. Finally the method is assessed by the solution of several numerical examples.