INVERSION PROBLEMS IN ELASTIC THIN SHELLS

The rapid advance of computers over the past 30 years has meant that n umerical solutions to problems concerning thin elastic shell structure s may now be obtained with relative ease. Such solutions, however, are often very time-consuming to produce. They may also be difficult to i nterpret, and frequently the abundance of data distracts from the prop er understanding of the phenomena being examined. The present paper in vestigates isotropic spherical and cylindrical elastic shells undergoi ng large deflections under radial point loading. Some straightforward experiments on an open-ended cylindrical shell are described, and the observed deformation behaviour under load is expressed in terms of rem arkably simple empirical formulae. Making use of finite element analys es, it is found that the deformation behaviour of cylindrical and sphe rical shells is in many respects similar. A careful examination of the data thus obtained leads to a thorough grasp of the processes involve d in the formation of the deformed surface. It is hoped that this unde rstanding may lead to a better comprehension of a variety of large-def lection phenomena observed in shell structures.