A benchmark problem where a cantilever is subject to a shear force at an end.
The reference results can be found in Sze KY, Liu XH, Lo SH. Popular 
benchmark problems for geometric nonlinear analysis of shells. Finite 
Elements in Analysis and Design 2004, 40(11):1551-1569.

Here the problem is solved by using a high-order discretization. Having a p-
element definition automatically switches to a special formulation (sets 
"Cartesian Formulation = Logical True"). 

