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references/README.md

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+# FESA Reference Artifacts
+
+This folder stores Abaqus input files and solved reference result artifacts used to verify FESA.
+
+Abaqus is not run by the repository validation flow. Files here are treated as stored numerical references after they are accepted.
+
+## Initial Accepted Files
+
+| Case | Input | Result Artifact | Notes |
+|---|---|---|---|
+| `quad_01` | `quad_01.inp` | `quad_01_displacements.csv` | Abaqus/CAE Learning Edition 2024 source input; displacement CSV has 121 nodal rows |
+
+## Displacement CSV Format
+
+`*_displacements.csv` files use Abaqus-exported nodal displacement columns:
+
+```text
+Node Label, U-U1, U-U2, U-U3, UR-UR1, UR-UR2, UR-UR3
+```
+
+Mapping to FESA:
+
+| CSV Column | FESA Component |
+|---|---|
+| `Node Label` | node id |
+| `U-U1` | `UX` |
+| `U-U2` | `UY` |
+| `U-U3` | `UZ` |
+| `UR-UR1` | `RX` |
+| `UR-UR2` | `RY` |
+| `UR-UR3` | `RZ` |
+
+## Compatibility Notes
+
+Stored Abaqus inputs may contain features outside the current FESA Phase 1 parser subset. Preserve the original files and document unsupported features instead of editing them in place.
+
+`quad_01.inp` currently includes `TYPE=S4R`, `Part/Assembly/Instance`, `*Density`, and `NLGEOM=YES`. These are stored for reference provenance and future compatibility work; they are not Phase 1 parser acceptance requirements unless `docs/ABAQUS_INPUT_SUBSET.md` and `docs/ADR.md` are updated.