2e28a69c047890761671b3a60b9e45f8fbeac451
4
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 jyvikoandClaude Opus 5.5
|
9469ac0853 |
Tet mesh quality: one validity criterion, Delaunay refinement, ODT, Klingner–Shewchuk, tet10
The end-to-end demo met a raw-CDT sliver that the validity gate accepted (exactly positive) and the solver refused. Now: - One validity criterion, `fieldcraft_model::admissible_jacobian` (normalized Jacobian above 1e-12), used by the implicit solver (fem `positive_inverse`), the explicit tet4/hex8 kinematics and the mesh gate, which proves it on the whole element (tet4: the solvers' own Jacobian; curved kinds: a Bernstein floor), so whatever passes the gate passes the solvers. - CDT rounding repaired by flips on the rounded mesh (Diazzi et al. 2023 §5.1) instead of the ±2-ulp nudge. - `fieldcraft-mesh::tet`: a mutable tetrahedral complex whose every change is a checked replacement (positive and admissible tetrahedra, faces matched with opposite orientation) with an exact undo log; edge removal (Klincsek), multi-face removal, Delaunay insertion with boundary faces, edge collapse; a curvature- and thickness-graded size field; constrained Delaunay refinement with encroachment splits; ODT smoothing; the Klingner–Shewchuk schedule; boundary vertices moved onto the exact B-rep surfaces at the end; tet10 with mid-edge nodes on the geometry. - `mesh.tet.generate` gains size, order, quality, quality_target, curvature_angle, grading, max_passes, max_points and reports the CDT's and the mesh's quality; `solve.probe` takes a set and reports its largest von Mises stress. - Oracle cases filleted-bracket-fillet-stress(-coarse): the fillet's peak von Mises stress on tet10 meshes of 2k and 13.5k elements, 213.3 MPa (a four-level study stays within 1.8%); the CDT cases keep the raw tetrahedralization. - Corpus quality columns: all 20 valid parts mesh and pass the gate. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm |
||
|
jyvikoandClaude Opus 5.5
|
2321d75cc6 |
fem: finite-strain material point, total Lagrangian elements and follower pressure
The material point interface returns the Kirchhoff stress and the spatial tangent of its Lie derivative from the deformation gradient, with per-point history committed by the solver: St Venant–Kirchhoff (pushed forward from S = D E) and the decoupled compressible neo-Hookean with its isochoric and volumetric parts. Total Lagrangian solids (tet4, tet10, wedge6, hex8, hex20 full and reduced) and plane strain and axisymmetric elements give internal forces and the consistent tangent with its geometric stiffness; hybrid solids use the Simo–Taylor–Pister three-field formulation on the existing pressure fields. Incompatible modes and plane stress are refused by name. Follower pressure on faces and 2D edges with its load stiffness. Every tangent is checked against central differences of its forces. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm |
||
|
|
bd55abea7f |
FEM foundation A: DofKind/DofLayout, shape-function library with Hessians, solvers on DofLayout (#35)
* fem: DofKind/DofLayout and the shape-function library with second derivatives DofKind (Ux..Rz, T, P), DofSet, ElementDofs (per-node kinds and condensed internal unknowns) and DofLayout: mesh nodes by label, kinds in order, then reference points. basis::Basis covers line2/3, tri3/6, quad4/8/9, tet4/10, wedge6/15, pyramid5, hex8/20/27 with values, first and second natural derivatives (second-order forward AD, fem::jet) and the physical gradients, Hessians and Laplacians with the map's second-derivative term. Tested for Kronecker delta, partition of unity, polynomial completeness, finite differences, affine and curved maps. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * solver, explicit: number degrees of freedom with DofLayout The implicit mesh numbers its unknowns with a DofLayout (mesh nodes by label with the kinds their elements declare, then six per coupled reference point); assembly adds element blocks by (node, DofKind), so a node may carry any mix of kinds; couplings, boundary conditions, loads and results address (node, kind). The explicit system keeps node-major translations, now checked against its layout (NODE_DOFS). Solid formulations declare their ElementDofs. Every static, frequency and explicit result of the solver, explicit, engine and io test suites hashes bit-identically before and after (957 results). docs/fem.md describes the DOF model and the shape-function conventions. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * fem, solver: simplify after review Block offsets resolved once per node pair; add_scalar/add_diagonal take the kinds like add_block; one checked Jacobian inverse (dense::positive_inverse) for the solid kernels and the basis library; static natural-node tables; the Hessian path inverts the Jacobian once. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm --------- Co-authored-by: jyviko <2501648+jyviko@users.noreply.github.com> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com> |
||
|
|
40f98f0af9 |
Implicit solver: fem kernels (tet4/10, hex8, hex20), sparse Cholesky, block Lanczos, solve.* commands (M4) (#23)
* Renumber the layer table for solver crates: fem at L1, solver at L2, fsi at L3 L0 model -> L1 geometry, mesh, fem, decks, render -> L2 solver (explicit, lbm later) -> L3 fsi (later) -> L4 doc -> L5 io -> L6 engine -> L7 ui-egui, mcp -> apps. UI_MIN_LAYER moves to 7, the testkit sits above it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * modelcraft-fem: element kernels for tet4, tet10, hex8 (full, incompatible modes), hex20 (full, reduced) Shape functions, Gauss and conical-product quadrature, stiffness, consistent and HRZ-lumped mass, body forces, consistent pressure loads on faces, integration-point stresses and their least-squares extrapolation to nodes, isotropic and orthotropic elasticity. The element table is one row per kind, so wedges, shells and beams are added locally. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * modelcraft-solver: linear static and frequency analysis with an analytic verification suite Assembly from the resolved model on the node graph, boundary conditions by elimination, consistent pressure, gravity and body-force loads, nested-dissection ordering, sparse up-looking Cholesky with a factor-size cap, reactions, integration-point and nodal-averaged stresses, von Mises; shift-invert block Lanczos with full reorthogonalization for natural modes, participation and effective mass. ADR 0001 records the own-linear-algebra decision (determinism, wasm). Verified against closed forms: displacement and traction patch tests for every element, cantilever tip deflection (Timoshenko) with convergence rates, Lamé cylinder, Kirsch hole (Kt -> 3), cantilever and free-free beam frequencies with six rigid-body modes. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * Engine: solve.static, solve.frequency and solve.probe; results kept in the session Results are stored per step, restored on a failed command and cleared when the model changes. Caps (degrees of freedom, factor entries, Lanczos vectors) may only be lowered; hostile parameters are tested against a solvable session. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * docs: implicit solver architecture, roadmap M4, parity and references Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * Simplify the solver: shared face integration, block assembly, cached extrapolation - model: one face integrator (nodal::face_normal_weights) for tractions and pressures - fem: mid-side tables from ElementKind::edges, orthotropic via inverse3, symmetric accumulation without a symmetrize pass, incompatible-mode recovery without K_uu, model's coordinate check, dead table rows removed - solver: one pattern search per node pair (block, scalar and diagonal adds), extrapolation built once per element type, reactions from the prescribed rows only, matrices dropped after restriction, the free-body shift keyed on the factorization error, step selection in the solver, Error::Element naming the element - engine: the solver owns the default step and the shift check; the model comparison runs once Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm * docs: results are stamped with the session revision Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm --------- Co-authored-by: jyviko <2501648+jyviko@users.noreply.github.com> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com> |