# Nonlinear Static Newton-Raphson Physics Evaluation

## 1. Metadata

| key | value |
| --- | --- |
| feature_id | `nonlinear-static-newton-raphson` |
| source reference comparison report | `docs/nonlinear-static-newton-raphson/reference-comparison.md` |
| source reference comparison SHA-256 | `22867B0F2E3C06C5AB908485D94160CA33CBAF1274EE099847979FA511ECC241` |
| source reference model | `docs/nonlinear-static-newton-raphson/reference-model.md` |
| source reference model SHA-256 | `B2E6845AB59A32F78261B7A47506C27F7BF4B61401B34BC5DE3DAD4F03D6ADDA` |
| status | `pass-for-release-agent` |
| owner_agent | `physics-evaluation-agent` |
| date | `2026-08-28` |

이 평가는 승인된 물리 acceptance scope와 이미 생성된 accepted-state evidence만 사용한다.
Abaqus 또는 다른 reference solver를 실행하지 않았고, 외부 solver의 내부 정식화·적분·안정화·
결과 복구 동등성을 주장하지 않는다.

## 2. Input Evidence

### 2.1 Gate-entry audit

- `implementation-report.md`와 `build-test.md`의 Stage 6 owner classification은
  `pass-for-physics-evaluation`이며 full CTest `302/302`, nonlinear reference `9/9` 통과를
  기록한다.
- Corrected required source `reference-comparison.md`는 overall handoff status를
  `pass-for-physics-evaluation`로 명시한다. Detailed verdict
  `blocking-pass-with-review-only-findings`는 모든 blocking numerical family가 통과하고 six
  local RF/RM findings만 review-only라는 세부 분류로 함께 유지된다. 두 status는 서로
  모순되지 않으며 `PHYS-STATUS-001`은 해소되었다.
- `requirements.md` metadata의 `status: draft`, `approved_by: pending user re-approval` 및
  `FESA-REQ-NSNR-069`의 historical `draft` 표시는 내용상 physics blocker가 아니다.
  Authoritative `coordination.md` Stage 1 record는 현재 requirements SHA-256
  `89C1AB5F1BEDB7C5F6AD0726ED62F0982181EA8746EDE4661183FD3D18A2408E`가
  `2026-08-27` 사용자에게 명시적으로 재승인되었고 Stage 1이 `passed`임을 기록한다.
  따라서 이 stale metadata를 승인 부재로 재해석하지 않는다.

### 2.2 Solver outputs and logs

| case | checked authoritative/generated evidence | SHA-256 / observed identity |
| --- | --- | --- |
| `shellnl-meshfine-s4-final` | build-local `shellNL-meshfine_results.h5` | `2E9817E173D73FD91C2D34864B69A1EC37483CB25951FB7CCE85895A6C87D2C6`; accepted frames 10; unique factor-one frame 9/increment 10; 2 iterations per increment |
| `shellnl-meshfine-s4-final` | build-local `shellNL-meshfine_log.txt` | `1DB6FE4AAA2F1443ACC7F9B3F919CC8DD873C90392121DAB6509F1693435DA27`; 20 entered-iteration records; each increment continues once and accepts on iteration 2 |
| `shellnl-s4-final` | build-local `shellNL_results.h5` | `130E2E7B73B022F216A7A34C88D58114A62595ADD556A0D202B8A7FAC7391F39`; accepted frames 10; unique factor-one frame 9/increment 10; 2 iterations per increment |
| `shellnl-s4-final` | build-local `shellNL_log.txt` | `3D5C4F1B20384655F9012ADE842B99E3B06B3799FC9AB16DD6FD141E18B77906`; 20 entered-iteration records; each increment continues once and accepts on iteration 2 |
| `shell-s4-linear-limit` | build-local `shell_results.h5`, `shell_log.txt` | HDF5 `8AEE34D5BC80382D7E6DE85C51F0F8BCBF451CD5F5C7B8DDA6C585EB22B31763`; zero-byte log `E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855` |

HDF5는 `reference-comparison.md`에 적힌 build-local exact path에서 직접 읽었다. Optional FESA
debug CSV view는 선언되거나 필요하지 않아 사용하지 않았다. Factor-one
`nodal/displacement`, `global/equilibrium`, `global/energy`, direct shell stress와
`accepted_frames`를 확인했다.

### 2.3 Read-only reference evidence

Canonical reference bundle은 `reference-comparison.md`가 inventoried한 12개 exact file을 사용했다.

- `reference/shellNL-meshfine/`: input, displacement, reaction, stress inventory
- `reference/shellNL/`: input, displacement, reaction, stress inventory
- `reference/shell/`: linear input, displacement, reaction inventory, stress inventory

각 SHA-256은 `reference-model.md`와 `reference-comparison.md` inventory에 일치한다. 비교량은
fine/coarse/linear `U1/U2/U3` blocking, `UR1/UR2/UR3` warning-only, fine/coarse local
`RF1/RF2/RF3`와 physical spatial `RM1/RM2` review-only다. `RM3`와 stored element-corner
stress는 numerical comparison에서 제외되었다.

Reference model의 목적은 중앙 `DOF 3=-100000` fixed-global dead load를 받고 둘레의 all-six
DOF가 고정된 `10 x 10`, thickness `0.5` square plate의 coarse/fine nonlinear response와
linear-limit source identity를 검증하는 것이다. Nonlinear cases는 `0.1` 간격으로 factor one까지
진행한다.

## 3. Physics Checks

| physics check | result | evidence and interpretation |
| --- | --- | --- |
| global equilibrium | `pass` | Fine normalized force `2.09625758e-12`, moment `2.74546602e-10`; coarse force `8.25122661e-12`, moment `1.41375091e-10`. 네 값 모두 approved inclusive `<=1e-8`다. HDF5 `/global/equilibrium`은 `location=global-balance-error`, current arm, global origin `[0,0,0]`, spatial moment 의미를 가진다. |
| reaction consistency | `pass` | Applied `F3=-100000`에 대해 constrained-reaction resultant `F3`는 fine/coarse 모두 약 `+100000`이고 다른 force components는 roundoff 수준이다. Applied-plus-reaction force/moment와 accepted free force/moment residual이 각각 blocking gate를 통과했다. Local RF/RM six-family discrepancy는 승인 계약상 review-only nodal redistribution evidence이며 global reaction/resultant identity를 대체하지 않는다. |
| displacement direction | `pass` | Downward load에 대해 node 2 final `U3`는 fine `-2.56338e-5`, coarse `-2.35504e-5`; reference도 각각 `-2.57957054e-5`, `-2.37408203e-5`다. HDF5 path는 factor `0.1..1.0`에서 fine `-2.56338e-6 .. -2.56338e-5`, coarse `-2.35504e-6 .. -2.35504e-5`로 부호 반전·jump·rollback 없이 진행한다. |
| symmetry / expected zero | `pass` | Center node 2의 factor-one `U1/U2`와 rotations는 fine/coarse에서 약 `1e-17` 이하로, centered load와 symmetric all-edge constraint의 expected-zero response와 일치한다. Fresh physics-focused CTest에서 finite rigid objectivity, zero internal force, rigid translation nullspace와 no-moment tangent symmetry checks가 통과했다. |
| element force balance | `covered-by-approved-invariants` | 승인 HDF5에는 standalone element nodal-action balance dataset이 없고 external element-force comparison도 요구되지 않는다. 대신 complete element residual/tangent same-trial identity, patch recovery, stable assembly covariance tests와 accepted global/free equilibrium gate가 문서화된 expectation을 충족한다. 별도 element-force output을 invent하지 않았다. |
| stress/strain | `pass-sanity-evidence` | HDF5 direct fixed-reference Gauss stress는 finite다. Element 1/GP1의 `[S11,S22,S12]`는 fine bottom `[-264846,-77843.6,914.879]`, middle `[1.94695,0.530775,-0.0224511]`, top `[264850,77844.8,-914.925]`; coarse도 bottom/top sign이 반대이고 middle이 작아 centered plate bending sign/thickness pattern과 일치한다. Stored CSV는 corner/SPOS-SNEG identity로 위치가 달라 numerical stress comparison이 승인되지 않았으므로 이를 tolerance pass로 재분류하지 않는다. |
| rigid body mode | `pass` | 둘레 all-six-DOF support가 global rigid-body motion을 제거하고, accepted path에 비정상 large translation 또는 singular/nonfinite 증상이 없다. Fresh focused tests에서 proper triad/director, finite rigid objectivity, zero internal force, rigid nullspace와 invalid branch rejection을 확인했다. |
| energy/residual | `pass-sanity-evidence` | Factor-one physical strain energy는 fine `1.28169`, coarse `1.17752`로 finite positive이며 near-linear relation `0.5*100000*abs(U3_center)`와 일치한다. 이는 secondary sanity evidence이고 승인 energy convergence gate는 아니다. Fine/coarse accepted free force/moment residual은 NSNR-069 blocking gate를 통과했고 log에는 nonfinite/failed accepted state가 없다. |
| model coverage | `pass` | Fine 729-node/676-element primary, coarse 49-node/36-element companion, linear control과 internal linear-limit/tangent/objectivity/patch/rollback portfolio가 승인 NSNR-030 scope를 덮는다. Stored response는 weak geometric-nonlinear regime이고 original-style MITC4의 curved/distorted membrane-locking risk는 알려진 한계지만 Numerical Review가 이번 release의 additional benchmark/convergence gate로 승인하지 않았으므로 model-coverage gap을 새로 만들지 않는다. |

Fresh physics-focused verification command:

```powershell
ctest --preset windows-msvc-ninja-debug -R '^(NonlinearMitc4Shell|NonlinearMitc4Recovery|NonlinearMitc4Residual|NonlinearMitc4Tangent|NonlinearMitc4Objectivity|NonlinearMitc4Patch|FiniteRotation|NonlinearStaticProcedure)\.' --output-on-failure
```

Result: `23/23` passed, exit `0`, total real time `5.12 s`.

## 4. Failure Classification

- blocking classification: 없음
- resolved finding: `PHYS-STATUS-001`; corrected `reference-comparison.md`가 required overall
  `pass-for-physics-evaluation` handoff와 detailed
  `blocking-pass-with-review-only-findings` verdict의 관계를 명시했다.
- observed failures: `equilibrium-failure`, `reaction-inconsistency`,
  `displacement-direction-failure`, `symmetry-failure`, `stress-location-failure`,
  `element-force-inconsistency`, `rigid-body-mode-suspected`, `nonfinite-result`,
  `model-coverage-gap`, `upstream-contract`, `environment` 모두 없음.

## 5. Evaluation Verdict

- verdict: `pass-for-release-agent`
- physics evidence disposition: documented equilibrium, reaction, displacement, symmetry/objectivity,
  stress/strain sanity, rigid-body, residual/path and model-coverage checks show no physical failure.
- pass disposition: documented physical expectations passed and no physics/model-coverage/I/O/upstream
  blocker remains.
- release meaning: this verdict authorizes Release Agent evaluation through Coordinator only. It is
  not Release approval, publish/deploy/package/tag authorization, or external-solver equivalence.

## 6. Handoff Recommendation

- handoff: `Release Agent`, always through `Coordinator Agent`
- recommendation: Release Agent는 current approved hashes, Stage 6
  `pass-for-physics-evaluation`, 이 문서의 `pass-for-release-agent`, known limitations와
  review-only findings를 사용해 release readiness만 audit한다.
- boundary: Physics Evaluation Agent는 release readiness, final release checklist, release notes,
  publish/deploy/package/tag를 승인하지 않는다.

## 7. No-Change Assertion

이 Stage 7 작업은 `docs/nonlinear-static-newton-raphson/physics-evaluation.md`만 생성했다.
Source code, tests, CMake, Harness, requirements, research, formulation, numerical review,
reference model, I/O contract, implementation reports, reference artifacts와 tolerance policy를
수정하지 않았다. Abaqus, Nastran 또는 다른 reference solver를 실행하지 않았다.

## 8. Open Issues

| id | severity | issue | gate effect |
| --- | --- | --- | --- |
| `PHYS-META-001` | nonblocking | `requirements.md`의 draft/pending metadata가 authoritative Coordinator/user reapproval record와 stale함 | 현재 hash의 explicit approval로 physics authority는 해소됨; Release traceability audit에서 투명하게 유지 |
| `PHYS-LOCAL-001` | nonblocking | six local RF/RM families have review-only discrepancies | approved disposition 유지; global force/moment balance와 free residual을 blocking evidence로 사용 |
| `PHYS-STRESS-001` | nonblocking | stored corner/SPOS-SNEG stress와 FESA direct Gauss recovery 위치가 다르고 fine optional stress row 하나의 node label이 malformed | stress numerical comparison 제외 유지; artifact를 repair하지 않음 |
| `PHYS-LIMIT-001` | known limitation | stored cases are weak geometric-nonlinear plate responses; original MITC4 has known curved/distorted membrane-locking risk | approved current portfolio에서는 blocker 아님; broader claim 금지 |