# Uniaxial stretch of a neo-Hookean block

A unit cube of 2 × 2 × 2 hex20 elements, symmetry planes x = 0, y = 0, z = 0, the face x = 1
pulled to x = 2 (λ = 2) in a nonlinear static step; E = 10, ν = 0.3 with the neo-Hookean
option (μ = 3.84615, κ = 8.33333). The lateral stretch l = 0.813143719 solves σ_yy = 0 (bisection
on the closed form), and σ_xx = 8.060135422. The deformation is homogeneous, so every element
reproduces it exactly.