Stresses and deformations in egg-shaped sludge digestors: membrane effects

Liquid-containment shells of revolution: A review of recent studies on strength, stability and dynamics

“…Junction and shell-discontinuity problems in egg-shaped liquid-containment shells of revolution were studied by Zingoni [69,70], with sludge digesters in mind. Such vessels comprised spherical portions of different radii smoothly joined to form a large tank of closed profile, in which bending disturbances occurred at the junctions on account of the abrupt changes in the meridional radius of curvature of the shell at these locations.…”

“…Of interest in the study were the membrane stresses generated in the shell as a result of the contained hydrostatic internal pressure, and, in particular, the discontinuity stresses that occur at the junctions of the various regions. The theoretical approach, closed-form analytical results, conclusions and design recommendations have been reported in a two-part article [69,70].…”

Studies on seismic performances of the prestressed egg-shaped digester with shaking table test

“…Remarkably, one can find that this shape also occurs in Figs. [8][9][10]. This means that there are some common features in different cases no matter whether the digester is filled with water or not and no matter what and how large ground acceleration is input.…”

“…The shells of the digesters are usually in a complex stress state and need careful studies [9,10]. On the other hand, particular importance should be attached to response analysis of the ESDs under earthquake because of the complexity of the problem and the prohibitively severe consequence of failure [11,12].…”

Equatorial bending of an elliptic toroidal shell

“…Junction stresses in various shell assemblies and multi-segmented vessels have been the subject of intensive studies over the past 15 years [21][22][23][24][25]. Mechanics phenomena around shell intersections and at shell-branching locations have also been of interest [26,27].…”