The finite element model of the ring stiffened cylinder is meshed with 26,796 SHELL281 elements with an element size of 10 mm. The fine mesh is required for buckling analysis, and a full 360-degree model is necessary because the deformation is no longer axisymmetric after buckling occurs.

All shell elements have uniform thickness. Five sections are created in the model with no offsets, so the shell sections are offset to the midplane by default.

The following figure shows the mesh (a) and the expanded solid representation (b) of the shell mesh (/ESHAPE):

Figure 21.1: Geometry and Finite-Element Model

a)
	Meshed shell model (/ESHAPE,0)
b)
	Expanded solid representation of the shell mesh (/ESHAPE,1)

This figure shows a cylinder sector of 45 degrees of the cylinder, plates and Z rings:

Figure 21.2: Inside View of a 45-Degree Sector

This figure shows the stiffening ring detail and its dimensions:

Figure 21.3: Stiffening Ring Detail with Dimensions