# Thick-walled cylinder under internal pressure, plane strain (Lamé)

A quarter of a cylinder a = 10, b = 20, one unit long, with symmetry planes x = 0 and y = 0 and
u_z = 0 on both ends (plane strain), and internal pressure p = 100 (E = 210000, ν = 0.3);
8 × 16 hex20 elements with mid-side nodes on the arcs. Lamé: u_r = (1 + ν)a²p/(E(b² − a²))
((1 − 2ν)r + b²/r), σ_θ(a) = p(b² + a²)/(b² − a²).