docs: add 3d euler beam phase

2026-06-12 17:26:01 +09:00
parent 825e03dbaf
commit 13cf2af899
13 changed files with 891 additions and 0 deletions
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+# Step 6: model-beam-topology
+
+## Read These Files First
+
+Read the following files before editing:
+
+- `/AGENTS.md`
+- `/docs/ARCHITECTURE.md`
+- `/docs/ADR.md`
+- `/docs/implementation-plans/euler-beam-3d-implementation-plan.md`
+- `/src/fesa/model/element.hpp`
+- `/src/fesa/model/element.cpp`
+- `/tests/unit/model_element_test.cpp`
+
+## Task
+
+Use TDD to add a semantic model topology for a two-node 3D beam.
+
+Required production behavior:
+
+- Add `beam2` to `fesa::model::ElementTopology`.
+- Preserve existing `truss2`, `bar2`, and `unknown` behavior.
+- Do not store equation IDs on `Element`.
+- Do not add section constants to `Element` in this step.
+
+## Tests To Write First
+
+Modify `/tests/unit/model_element_test.cpp` first.
+
+Add a failing assertion that constructs an element with:
+
+- id `ElementId{10}`
+- topology `ElementTopology::beam2`
+- node ids `{NodeId{1}, NodeId{2}}`
+- property id `PropertyId{7}`
+
+The test must verify:
+
+- `element.topology() == ElementTopology::beam2`
+- `element.node_ids().size() == 2`
+- existing `bar2` behavior still works or the test still covers it
+
+RED command:
+
+```powershell
+ctest --test-dir build/msvc-debug --output-on-failure -C Debug -R model_element_test
+```
+
+Expected RED: compile failure because `ElementTopology::beam2` is not defined.
+
+Then implement the minimal enum addition.
+
+GREEN command:
+
+```powershell
+ctest --test-dir build/msvc-debug --output-on-failure -C Debug -R model_element_test
+```
+
+## Acceptance Criteria
+
+```powershell
+ctest --test-dir build/msvc-debug --output-on-failure -C Debug -R model_element_test
+python -m unittest discover -s scripts -p "test_*.py"
+python scripts/validate_workspace.py
+```
+
+## Verification Notes
+
+1. Confirm the test failed before editing production code.
+2. Confirm no unrelated model refactor was made.
+3. Update `phases/euler-beam-3d/index.json` step 6:
+   - success: `"status": "completed"`, `"summary": "beam2 model topology added with unit test"`
+   - failure after retries: `"status": "error"`, `"error_message": "<specific error>"`
+   - blocked: `"status": "blocked"`, `"blocked_reason": "<specific reason>"`
+
+## Forbidden
+
+- Do not create parser code.
+- Do not add beam stiffness code in this step.