# Yeoh block in uniaxial tension

One hybrid hex20 unit cube on three symmetry planes, E = 3, ν = 0.49, Yeoh with C₁₀ = μ/2,
C₂₀ = −0.02 and C₃₀ = 0.004, pulled to λ = 2 in a nonlinear static step. The reference is the
compressible decoupled energy's axial Cauchy stress σ = (λ/J) ∂W/∂λ with the lateral stretch
found by bisection so σ_yy = 0.