Thin-walled cylindrical shells: notes
This form may be used for cylindrical shells and pipes of any length. However no value of the abscissa, for which are calculated stress and
deflection values, may be greather than 20/l. If ll>20, end B is considered to be
at xB=20/l and maximum values are calculated only in the interval
0-xB. All values calculated inside that interval are correct.