feat(hydrotech-beam): Phase 1 LHS DoE study code
Implements the optimization study code for Phase 1 (LHS DoE) of the
Hydrotech Beam structural optimization.
Files added:
- run_doe.py: Main entry point — Optuna study with SQLite persistence,
Deb's feasibility rules, CSV/JSON export, Phase 1→2 gate check
- sampling.py: 50-point LHS via scipy.stats.qmc with stratified integer
sampling ensuring all 11 hole_count levels (5-15) are covered
- geometric_checks.py: Pre-flight feasibility filter — hole overlap
(corrected formula: span/(n-1) - d ≥ 30mm) and web clearance checks
- nx_interface.py: NX automation module with stub solver for development
and NXOpen template for Windows/dalidou integration
- requirements.txt: optuna, scipy, numpy, pandas
Key design decisions:
- Baseline enqueued as Trial 0 (LAC lesson)
- All 4 DV expression names from binary introspection (exact spelling)
- Pre-flight geometric filter saves compute and prevents NX crashes
- No surrogates (LAC lesson: direct FEA via TPE beats surrogate+L-BFGS)
- SQLite persistence enables resume after interruption
Tested end-to-end with stub solver: 51 trials, 12 geometric rejects,
39 solved, correct CSV/JSON output.
Ref: OPTIMIZATION_STRATEGY.md, auditor review 2026-02-10
Antoine
017b90f11e