forked from 1b-agent/fieldcraft-upstream
jyvikoandClaude Opus 5.5
d586d84859
Five cases against closed forms: a Mooney-Rivlin block in Treloar's uniaxial, equibiaxial and pure-shear modes and a Yeoh block in uniaxial tension (the compressible energy's stresses, exact); a stretched Mooney-Rivlin tube inflated by a follower pressure (Rivlin's incompressible solution, 0.6 % at nu = 0.4995); free and fully held thermal expansion at a thermal stretch of 1.2 (exact); a bar held at its ends heated past yield (exact). docs/fem.md, the literature, ROADMAP (M15, M17), parity and the oracle page follow. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm
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.