1 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Opus 5	8615fc5783	rtx-fea: verify elastostatics by manufactured solution — second order confirmed ... Adds the Method of Manufactured Solutions to this crate, and it immediately paid for itself by finding a bug that every existing test missed. MMS asserts something stronger than "close enough to a value someone believed": that the discretisation converges to the exact solution at the rate the theory predicts. Choose a smooth field, substitute it into the governing equations, and whatever they fail to balance is the body force that makes it exact. Solve, refine, read off log2(e_h / e_h/2). Observed order for Quad4 displacement in L2: n = 8 L2 error = 7.816681e-3 order - n = 16 L2 error = 1.962845e-3 order 1.99 n = 32 L2 error = 4.912786e-4 order 2.00 (n = 64 reads 2.00 as well, at ten times the cost) That verifies the whole chain at once -- element matrices, quadrature, Jacobian, assembly, DOF numbering, constraints and the linear solver -- against a solution none of them can represent exactly. It is the check that none of the sixteen defects fixed in this crate would have survived. The manufactured field is u = sin(pi x) sin(pi y), v = x^2(1-x) y(1-y): smooth, not in the bilinear element space, with the two components different in form and a non-zero shear strain, so the shear block of the constitutive matrix is exercised rather than skipped. Found by it: `compute_shape_functions` inferred how many parametric coordinates to pass from the coordinate *values* -- match coords.eta() { 0.0 if coords.zeta() == 0.0 => vec![coords.xi()], // 1 component ... -- so any evaluation on an axis was handed a one-component slice, which every 2-D and 3-D element rejects. That includes the element centre and the middle point of every odd-order Gauss rule. It survived only because the default 2-point rule never samples zero; asking for a 3-point rule to integrate the error was enough to trip it. Dimensionality now comes from the element, which is where it belongs. Two prerequisites, both real functional gaps rather than test scaffolding: - Consistent body-force integration. `BodyForceBC` distributed load as force * volume / num_nodes, which is exact only for a constant force on a symmetric element and otherwise first-order -- enough to cap the measured order of the whole solver at 1 regardless of the element. `ElementMatrixComputer::compute_body_force_vector` now integrates the consistent form, taking the force as a closure so a spatially varying load can be expressed at all. - Non-homogeneous Dirichlet conditions did not exist. `StaticLinearAnalysis` read the prescribed value out of the boundary condition and discarded it, and `extract_free_system` built the reduced right-hand side without the K_fc u_c coupling, so every Dirichlet condition behaved as zero whatever the caller asked for. `GlobalSystem::set_prescribed_value` and the coupling term close that, reusing `extract_submatrix` and `multiply_vector` rather than a dof-by-dof loop. 560 tests across the three crates, 0 failing. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>	2026-08-19 12:04:46 -07:00