jyvikoandClaude Opus 5.5
945a2076c3
Two oracle cases: the contact patch test on non-matching meshes in small and finite sliding, and Hertz's cylinder on a flat under force control (peak pressure, pressure distribution, subsurface stress). docs/fem.md describes the formulation, the literature survey its papers; ROADMAP M7 and parity are updated. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Hertz line contact: cylinder on a flat (implicit mortar contact)
A steel cylinder of radius R = 10 mm pressed on a steel block (E = 210 GPa, ν = 0.3; mm, N, MPa) in plane strain: a quarter model of the cylinder's lower part (a 2.5 mm wide block whose bottom is the circular arc, graded towards the contact) on a 5 × 5 mm foundation, symmetric about x = 0, one element thick with every node held in z. A pressure on the indenter's top carries the load P = 2265.57 N/mm (per length of the whole cylinder) chosen so that Hertz's half-width is b = 0.5 mm and the peak pressure p₀ = 2884.6 MPa. Soft springs (0.01 N/mm per node) hold the indenter's top vertically until the contact closes. One nonlinear static step without nonlinear geometry: small sliding, mortar contact of the round face (secondary) on the flat (main) by an augmented Lagrangian.