2 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Fable 5	4da70faa1e	rtx-fea: QM6 as an opt-in bending path; cantilever pinned to Euler-Bernoulli directly ... The QM6 incompatible-modes stiffness existed and was verified (compute_stiffness_matrix_incompatible) but nothing could reach it: the assembler always routed Quad4 through the compatible element. AssemblyOptions gains use_incompatible_modes (default false — every existing matrix is byte-identical, which the manufactured-solution verification depends on), threaded through GlobalAssembler into StandardFiniteElement; element types QM6 does not apply to keep their standard stiffness either way. What it buys, measured on the cantilever first bending mode against Euler-Bernoulli's 40.3848 Hz: mesh QM6 (error) compatible (error) 8x2 40.4020 (+0.04%) 81.8102 (+102.6%) 16x4 40.3402 (-0.11%) 53.8022 (+33.2%) 32x8 40.3242 (-0.15%) 44.0796 (+9.2%) The frequency is now asserted against the closed form directly (0.5% band) instead of as convergence-from-above, plus the condensation theorem — QM6 can only soften, so its frequency must sit at or below the compatible one on every mesh. The slight undershoot on finer meshes is physical: the 2-D solid carries the transverse shear flexibility the beam theory neglects. 552 rtx-fea tests, 0 failing. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-19 19:47:25 -07:00
Omar SobhandClaude Opus 5	4c2cea36aa	rtx-fea: make the analysis stack produce physics, validated against closed form ... The census found rtx-fea could not produce a non-zero answer for any analysis type. Six defects sat between a correctly specified mesh and a natural frequency, each of which alone was fatal. Every one was found by writing the closed-form test first and confirming red. 1. Element matrices were a stub. StandardFiniteElement:: compute_element_matrices returned DMatrix::zeros for stiffness, force and mass -- and it is what GlobalAssembler calls for every element, so every global matrix in the crate was zero. Real quadrature-based stiffness and mass already existed in ElementMatrixComputer; nothing called them. Now wired, with the scalar mass matrix expanded by a Kronecker product with the spatial identity to match the interleaved per-node DOF layout its stiffness uses. 2. Quadrature returned no points. quadrature_rule built QuadratureRule::new(vec![], ..). Every integration loop iterates over rule.points, so an empty rule does not fail -- it skips the loop and yields a zero matrix. Real Gauss rules for line, triangle, quad, tet and hex existed unused; now dispatched by element type, with wedges as the triangle-line tensor product and pyramids an explicit error rather than an empty rule. 3. transform_derivatives computed J^-T * dN where dN is (num_nodes x param_dim). By the chain rule it is dN * J^-1. The two agree only when both are square and symmetric; for any element with more nodes than parametric directions -- every element -- the old form was a dimension mismatch that panicked inside BLAS. 4. MaterialDatabase::clone silently dropped every material, cloning names only, because Box<dyn Material> is not Clone. GlobalAssembler is constructed with materials.clone(), so every assembler ever built got an empty database and every analysis failed MaterialNotFound on a correctly specified mesh. Materials are immutable once registered, so the map now holds Arc and cloning shares them. 5. displacement_only numbered three displacement components on a 2-D mesh. Elements supply two, so assembly rejected every contribution. 6. to_dof_numbering pushed each node's DOFs in HashMap iteration order. When that came out [v, u] the assembler wrote the element's u row into the global v row. The result was still symmetric, still had the right rigid-body null space and still summed to the right total mass -- it simply described a structure with its axes transposed per node, and get_dof(node, DisplacementX) then pointed at the wrong row so constraints were applied to the wrong direction too. DofComponent now carries a canonical_index and the DOFs are sorted by it. ModalAnalysis is wired to real assembly and the repaired eigensolver, and takes boundary conditions, which it previously had no way to accept. The eigensolver now rejects a singular stiffness explicitly: try_inverse does not fail on a matrix singular only to working precision, so an unconstrained structure used to return rigid-body noise dressed up as low-frequency modes. Validation, 18 tests: - Element matrices: rigid translation stores no energy, exactly 3 rigid-body modes in 2-D and 6 in 3-D, consistent mass integrates to rho*V, mass positive definite, and K and M each scale only with the property they depend on. A zero matrix passes symmetry and does-not-crash checks, so these are chosen to be ones it fails. - Modal, end to end: longitudinal modes of a fixed-free bar against f_n = (2n-1)/(4L) sqrt(E/rho), within 1% on the first three, and second-order convergence under refinement. Axial rather than cantilever bending on purpose: Quad4 shear-locks, so a bending tolerance would fail for a reason unrelated to correctness. Bending is asserted as convergence from above instead, which is the honest claim for a locking element. Two fixtures corrected rather than tolerances loosened: integration_tests expected 27 DOFs for a 9-node planar mesh (3 components per node), which encoded defect 5 and contradicted comprehensive_tdd_tests asserting num_nodes * 2 for the same situation. rtx-fsi stays 26/26. No new failures; the rtx-cfd quarantine is unchanged. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>	2026-08-19 08:10:57 -07:00