ABSTRACT
ABSTRACT: In this paper a general approach to the analysis of axisymmetric stress states at arbitrary shell junctions of thin-walled axisymmetric shell structures is presented which is based on a newly developed effectivering analogy model. The axisymmetric elastic stiffness of this analogous effective ring is equivalent to the axisymmetric elastic boundary stiffness of the related shell segment. The effective ring has a two-point crosssection with one point located at the shell boundary and the other one located excentrically above the plane of the circular boundary. The ring is capable of exactly representing the linear-elastic static force-deformation behaviour due to uniform radial boundary forces and meridional boundary moments acting at the edges of long axisymmetric shell segments, i.e. exact in the sense of Geckelers approximation. This ring girder analogy represents a long-searched missing link and the resolution of a paradox, since the Geckeler approximation suggests an analogy between the edge bending effects of (long and steep) general shell of revolution and the cylindrical shell. However, this analogy has only restricted validity, i.e. for the governing differential equation and fundamental solutions, but not for the solutions of the boundary value problem. The well-established effective area model, quite naturally, represents a special case of this more general effective ring model by restraining the meridional rotations. The analysis procedure developed in this paper is general, yet straightforward to apply and simple enough to be used in daily engineering work or to be included in future design codes. The effectiveness of the proposed analogy model is demonstrated by practical examples.
