0.2.6 G04 controlled contract¶
Status and boundary¶
G04 is the official Linear / element robustness gate. This document and the
machine-readable files beside it define a controlled execution contract; they
do not close G04, change the global gate manifest, or promote a capability.
The base claim is limited to linear_static, small-displacement, linear-elastic
routes already present in the capability registry. Unsupported combinations are
expected to be rejected. Modal, dynamic/Newmark, harmonic, buckling, J2,
geometric nonlinear/TL, arc-length, contact, RBE extensions, and any new
formulation are outside this contract.
The source of truth is:
- contract:
qualification/0_2_6/g04_requirements.json; - case mapping:
qualification/0_2_6/g04_case_mapping.json; - capability maturity:
qualification/capability_registry.json; - case execution state:
qualification/0_2_6/case_registry.json.
Element and route matrix¶
| Element | Material route | Linear static loads | Boundary conditions | Expected V&V | Known boundary |
|---|---|---|---|---|---|
| BEAM2 | beam_isotropic |
nodal, line load | fixed/prescribed DOFs | L2 | variable sections and curved beams excluded |
| MITC3 / MITC3+ alias | shell_isotropic |
nodal | fixed/prescribed DOFs | L2 | laminate route deferred from base claim |
| MITC4 | shell_isotropic |
nodal, pressure, surface/edge traction | fixed/prescribed DOFs | L2 | laminate route deferred from base claim |
| TET4 | isotropic_3d |
nodal, gravity, body force, pressure, surface traction | fixed/prescribed DOFs | L3 | coarse flexure and near-incompressibility bounded by existing limits |
| TET10 | isotropic_3d |
nodal, gravity, body force, pressure, surface traction | fixed/prescribed DOFs | L3 | positivity is sampled, not globally proven |
| HEX8 | isotropic_3d |
nodal, gravity, body force, pressure, surface traction | fixed/prescribed DOFs | L3 | finite-kinematic and J2 routes excluded |
| HEX20 | isotropic_3d |
nodal, gravity, body force, pressure, surface traction | fixed/prescribed DOFs | L3 | finite-kinematic and J2 routes excluded |
| DISCRETE | discrete_linear |
nodal | fixed/prescribed DOFs | L2 | the existing 0.2.6 record is planned/mixed and is not a ready base case |
MITC3+ is an alias used in documentation for the registered MITC3 capability; it is not a new registry element or an invented combination.
Requirements and evidence levels¶
| ID | Requirement | Evidence expected |
|---|---|---|
| G04-LIN-001 | route and element dispatch | supported declarations pass; unsupported combinations reject deterministically |
| G04-LIN-002 | patch/constant strain and rigid-body behaviour | analytical patch or invariant where mathematically applicable |
| G04-LIN-003 | load diversity and equilibrium | compatible distributed loads, reaction resultant/moment, free residual |
| G04-LIN-004 | material and orientation boundaries | isotropic routes; orientation only where formulation supports it; laminate deferred |
| G04-LIN-005 | mesh refinement, quality and distortion | coarse/medium/fine continuum sequences and recorded quality metrics |
| G04-LIN-006 | invalid inputs and failure modes | safe rejection of degenerate/inverted mesh and invalid data |
| G04-LIN-007 | compatible external correlation | pinned tool/version and identical model data; unavailable tools are skipped, never pass |
| G04-LIN-008 | provenance and anti-forgetting | SHA, clean state, environment, case IDs, digests, registry and requirement links |
The mapping currently contains 72 LIN/SHL registry records: 65 READY, 4
PLANNED, and 3 NOT_APPLICABLE. READY records originating in G05 or G06
are explicitly reuse candidates and cannot be counted twice for a future G04
closeout. The three planned SHL records declare mixed and have no executable
input model, so they remain traceability records rather than G04 base claims.
Proposed minimums and Owner-approved policies¶
The per-element minimums remain deliberately marked
PROPOSED_OWNER_REVIEW in the JSON contract. They are not gate-close
thresholds. The Owner approved bounded policies for execution are:
| Element | Proposed unique cases | Required route samples |
|---|---|---|
| BEAM2 | 2 | nodal, line load |
| MITC3 | 2 | membrane, bending or shear |
| MITC4 | 3 | membrane, bending, pressure or edge traction |
| TET4/TET10/HEX8/HEX20 | 3 each | traction/compression, distributed load, refinement |
| DISCRETE | 1 | nodal static spring or mass |
Existing policies remain authoritative: exact invariants, the existing
deterministic floating-point foundation policy, case-defined analytical error,
and SKIPPED_EXTERNAL_UNAVAILABLE for unavailable external tools. The Owner
approved bounded policies require free residual <=1e-8, force and moment
balance <=1e-10, and a final adjacent-mesh response change <=1% over at
least three compatible levels. Warning bands are not PASS criteria. The mesh
policy requires a predeclared observable and explicitly does not require
monotonicity for singular, discontinuous or formulation-dependent fields. No
tolerance is weakened by this contract.
Execution and approval¶
Execution must emit per-case inputs, source SHA, clean-worktree state, solver settings, results, audit checks, oracle provenance, tolerance provenance, and an artifact manifest. Registry and anti-forgetting checks are prerequisites. An Owner decision is required before any official G04 closeout; the global G04 manifest remains unchanged by this preparation.