## 5. Slightly Curved Cylindrical Panel

The test case consists of the calculation of the linear buckling load
of a slightly curved cylindrical panel, using different element types. Only
one quarter of the plate has been modelled. The panel is modelled with the
shell elements available in B2000++.

The panel has a length L=92mm along the straight edges, a radius
R=586mm with an angle
α
of 9 degrees along the curved edges and a thickness
t=1mm. The mesh grid is 7 by 7 nodes in both directions.

The material is linear isotropic, with modulus of elasticity
E=7*10^{4}N/mm^{2} and
ν=0.3.

Line loads are applied on edge I in the positive z direction. Edge I
has suppressed displacements in radial direction and edge IV is simply
supported. Edges II and III have symmetry boundary conditions.

No analytical solutions are available for this problem. The results of
the analysis, i.e the buckling load values, can be consulted in the test
file `__init__.py`

. The figure below display the
convergence behaviour of this problem.