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TL Boundary Owner Pre-validation

Status: PASS_DIAGNOSTIC; this decision approves bounded diagnostic policies and does not promote Total-Lagrangian capability.

Provenance

  • Decision start SHA: 3601e13263960e854d2b1c3231ba115b6ddc3990
  • Campaign source SHA: 5d16ab839679dcee64e6251085ba52c4b494847c
  • Campaign capture: dirty=false
  • Controlled decision: qualification/0_2_6/tl_boundary_study/tl_boundary_owner_prevalidation.json

Owner-approved bounded policies

Mesh

MESH_POLICY = OWNER_APPROVED_BOUNDED

  • No universal threshold is derived from nominal aspect ratio alone.
  • Jacobian, mesh quality/distortion and measured diagnostics are mandatory checks.
  • The stable, degraded and out-of-scope zones describe the tested domain only.

Tangent conditioning

CONDITIONING_POLICY = OWNER_APPROVED_BOUNDED

  • Tangent conditioning remains a mandatory diagnostic.
  • No universal numeric cutoff is approved.
  • Severe conditioning together with Newton failure remains explicit and fail-closed.

Adaptive cutback

ADAPTIVE_CUTBACK_POLICY = OWNER_APPROVED_BOUNDED

  • Opt-in cutback is allowed as a robustness mechanism.
  • Rollback is mandatory.
  • Reaching the minimum increment is an explicit failure.
  • Adaptive recovery never erases the fixed-step history.

Frozen evidence

Item Result
TET4 cases 75
HEX8 cases 75
Fixed-step successes 134/150
Adaptive successes 146/150
Recovered by cutback 12
Failed in both modes 4
Stable conditioning median ~3.97e3
Degraded conditioning median ~9.25e4
Out-of-scope conditioning median ~8.22e6

The four persistent failures, the twelve degraded cases and the historical CASE2 anchor remain in the failure zoo. These values are observations, not acceptance thresholds.

Technical decision

  • TL_FORMULATION_FIX_REQUIRED = NO
  • NEWTON_FIX_REQUIRED = NO
  • TL_BOUNDARY_STUDY = PASS_DIAGNOSTIC
  • TL_PROMOTION = DEFERRED
  • 026-G07 remains NOT_STARTED; this pre-validation does not close it.
  • CONTRACT_LOWERED = NO

The next step is a separate TL numerical robustness R&D plan. No R&D implementation, Arc-Length/G08 work or promotion is authorized by this document.