LE4: Axisymmetric hyperbolic shell under uniform internal pressure

This is a test recommended by the National Agency for Finite Element Methods and Standards (U.K.): Test LE4 from NAFEMS publication TNSB, Rev. 3, “The Standard NAFEMS Benchmarks,” October 1990.

Target solution: On the midsurface at point K the meridional stress, ${\sigma }_{\varphi \varphi }$, is −50.0 MPa and the hoop stress, ${\sigma }_{\theta \theta }$, is 50.0 MPa.