LOCAL-GLOBAL ANALYSIS ON LOCALIZED NONLINEAR SHELLS OF REVOLUTION

A finite element program is developed as a tool to analyse shells of r evolution with local non-linearities. In reality, shells of revolution often exhibit local deviations, like a cut-out, a junction and/or an imperfection. The stress concentration around a local deviation may pr oduce plasticity and/or geometric non-linearities in the surrounding r egion. The analytical model consists of three different types of eleme nts: rotational, transitional and general. The rotational shell elemen ts are used in the region where the shell is axisymmetrical and linear , while the two-dimensional general shell elements are deployed in the deviation region where non-linearities may occur. Transitional shell elements connect the two distinctively different types of elements to achieve displacement field continuities. The solution using the local- global system with appropriate condensation and a predicted stress inc remental procedure is suggested. It is shown that the technique is a v ery attractive alternative to the entirely general element style analy sis for axisymetric shell structures with local deviations.