ABSTRACT
In general, a body is considered a shell/plate when the contribution of shear deformations becomes non-significant and can be neglected. This happens when the ratio between the span of plate-bending curvature/the projected span of curvature and the shell thickness is larger than 10:1. According to some authors, this formulation itself is adequate and can be applied for a ratio down to 5:1 (https://wiki.csiamerica.com).
